ICSE 10 years Question paper From 2007 to 2019

 

ICSE Physics 10 Years Question Paper

ICSE Paper 2007
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) Which class of levers has a mechanical advantage always greater than one ?
What change can be brought about in this lever to increase its mechanical advantage ?  [2]

(b) Two bodies, A and B of equal mass are kept at heights 20 m and 30 m respectively. Calculate the ratio of their potential energies.  [2]

(c) What is the S.I. unit of upthrust ? Mention one factor on which the upthrust of a liquid depends.  [2]

(d) Why are infra-red radiations preferred over ordinary visible light for taking photo-graphs in fog ? [2]

(e) Define Relative density of a substance.  [2]

Question 2:
(a) Mention two reasons why water is not a suitable barometric liquid.  [2]

(b) State Snell’s Law of Refraction of light.  [2]

(c) (i) What will be the colour of a blue flower when it is seen in magenta coloured light ?
(ii) Name another secondary colour of light in which the flower will show the same colour as it shows in the magenta coloured light.  [2]

(d) The upper blood pressure of a patients 160 cm of mercury whereas the normal blood pressure should be 120 cm of mercury. How much extra pressure is generated by the heart above the normal pressure ? (Give your answer in S.I. unit)
(Density of mercury = 13600 kg m^-3; g = 9.8 ms^-2).  [2]

(e) Draw an approximate graph to show the variation of atmospheric pressure with altitude.  [2]

Question 3:
(a) Define the terms :
(i) Amplitude (ii) Frequency (as applied to sound waves.)  [2]

(b) An object is placed in front of a converging lens at a distance greater than twice the focal length of the lens. Draw a ray diagram to show the formation of the image.  [2]

(c) Mention one difference between reflection of light from a plane mirror and total internal reflection of light from a prism.  [2]

(d) The V-I graph for a series combination and for a parallel combination of two resistors is as shown in the figure below:

Which of the two, A or B, represents the parallel combination ? Give a reason for your answer.  [2]

(e) Of the three connecting wires in a household circuit:
(i) Which two of the three wires are at the same potential ?
(ii) In which of the three wires should the switch be connected ?  [2]

Question 4:
(a) What will an alpha particle change into when it absorbs:
(i) One electron;
(ii) Two electrons ?  [2]

(b) Some hot water was added to three times its mass of cold water at 10°C and the resulting temperature was found to be 20°C. What was the temperature of the hot water ?  [2]

(c) Calculate the value of the resistance which must be connected to a 15 Ω resistance to provide an effective resistance of 6 Ω.  [2]

(d) Why are burns caused by steam more severe than those caused by boiling water at the same temperature ?  [2]

(e) Mention two important properties of a metal that make it a good thermionic emitter.  [2]

SECTION-II (40 Marks)

Answer any four questions from this Section.

Question 5:
(a) (i) Define a kilowatt hour. How is it related to the joule ?
(ii) How can the work done by measured when force is applied at an angle to the direction of displacement ?  [3]

(b) (i) What is the main energy transformation that occurs in :
(1) Photosynthesis in green leaves; (2) Charging of a battery.
(ii) Write an expression to show the relationship between mechanical advantage, velocity ratio and efficiency for a simple machine.  [3]

(c) A block and tackle pulley system has a velocity ratio 3.
(i) Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the directions of the load and effort.
(ii) Why should the lower block of this pulley system be of negligible weight ?  [4]

Question 6:
(a) (i) Name and state the principle on which the working of a hydraulic machine is based.
(ii) A balloon filled with hydrogen rises to a certain height and then stops rising. Why does it stop rising ?  [3]

(b) (i) State Archimedes Principle.
(ii) Explain why a piece of iron sinks in water while a ship made of iron floats.  [3]

(c) A piece of wood of volume 200 cm³ and density 0.84 g cm^-3 floats in a liquid of density 1.05 g cm^-3.
(i) What volume of wood will remain above the surface of the liquid ?
(ii) What force must be exerted on the wood to keep it totally submerged ?  [4]

Question 7:
(a) The diagram given alongside shows a right-angled prism with a ray of light incident on the side AB. (The critical angle for glass is 42°).

(i) Copy the diagram and complete the path of the ray of light in and out of the glass prism.
(ii) What is the value of the angle of deviation shown by the ray ?  [3]

(b) (i) A particular type of high energy invisible electromagnetic rays help us to study the structure of crystals. Name these rays and give another important use of these rays.
(ii) How does the speed of light in glass change on increasing the wavelength of light ?  [3]

(c) (i) With the help of a well-labelled diagram show that the apparent depth of an object, such as a coin, in water is less than its real depth.
(ii) How is the refractive index of water related to the real depth and the apparent depth of a column of water ?  [4]

Question 8:
(a) A man standing in front of a vertical cliff fires a gun. He hears the echo after 3 seconds. On moving closer to the cliff by 82.5 m, he fires again. This time, he hears the echo after 2.5 seconds. Calculate :
(i) The distance of the cliff from the initial position of the man.
(ii) The velocity of sound.  [3]

(b) (i) What is meant by Specific heat capacity of a substance ?
(ii) Why does the heat supplied to a substance during its change of state not cause any rise in its temperature ?  [3]

(c) A substance is in the form of a solid at 0°C. The amount of heat added to this substance and the temperature of the substance are plotted on the following graph:

If the specific heat capacity of the solid substance is 500 J/kg°C, find from the graph
(i) The mass of the substance;
(ii) The specific latent heat of fusion of the substance in the liquid state.  [4]

Question 9:
(a) (i) What is meant by earthing of an electrical appliance ? Why is it essential ?
(ii) What will be the effect on the working of an electric bell if instead of a direct current, an alternating current is used ?  [3]

(b) (i) State two factors on which the strength of an induced current depends.
(ii) When a solenoid that is carrying current is freely suspended, it comes to rest along a particular direction. Why does this happen ?  [3]

(c) A cell of e.m.f 1.5 V and internal resistance 10 Ω is connected to two resistors of 4.0 Ω and 20.0 Ω in series as shown in the figure :

Calculate the:
(i) Current in the circuit.
(ii) Potential difference across the 4.0 Ω resistor.
(iii) Voltage drop when the current is flowing.
(iv) Potential difference across the cell.

Question 10:
(a) Name the three main parts of a hot cathode ray tube. Mention one important function of each of the three main parts.  [3]

(b) (i) State the principle on which The functioning of a nuclear reactor is based.
(ii) Name a material that can be used as fuel in a nuclear reactor.
(iii) How is the activity in a nuclear reactor controlled ?  [3]

(c) (i) What happen to the atomic number of an element when it emits :
(1) an alpha particle;
(2) a beta particle.
(ii) Explain why alpha and beta particles are deflected in an electric or a magnetic field but gamma rays are not deflected in such a field.  [4]

 

ICSE Paper 2008
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) Name the SI unit of:
(ii) Linear momentum
(ii) Rate of change of momentum.  [2]

(b) A body of mass 1.50 kg is dropped from the 2nd floor of a building which is at a height of 12 m. What is the force acting on it during its fall ?
(g = 9.80 ms^-2)  [2]

(c) When an arrow is shot from a bow, it has kinetic energy in it. Explain briefly from where does it get its kinetic energy ?  [2]

(d) What energy conversions take place in the following when they are working:
(i) Electric toaster (ii) Microphone ?  [2]

(e) Copy the diagram of the forearm given below, indicate the positions of Load, Effort and Fulcrum.  [2]

Question 2:
(a) (i) A monochromatic beam of light of wavelength X passes from air into a glass block. Write an expression to show the relation between the speed of light in air and the speed of light in glass.
(ii) As the ray of light passes from air to glass, state how the wavelength of light changes. Does it increase, decrease or remain constant ?  [2]

(b) In what way will the temperature of water at the bottom of a water fall be different from the temperature at the fop ? Give a reason for your answer.  [2]

(c) A radar sends a signal to an aeroplane at a distance 45 km away with a speed of 3 x 108 ms-1. After how long is the signal received back from the aeroplane ?  [2]

(d) Draw a ray diagram to illustrate the determination of the focal length of a convex lens using an auxiliary plane mirror.  [2]

(e) What is meant by primary colours ? Name the primary colours of light.  [2]

Question 3:
(a) (i) Sketch a graph to show the change in potential difference across the ends of an ohmic resistor and the current flowing in it. Label the axes of your graph. (ii) What does the slope of the graph represent ? [2]

(b) Draw a labelled diagram of the staircase wiring for a dual control switch showing a bulb in the circuit.  [2]

(c) The electrical gadgets used in a house such as bulbs, fans, heater, etc., are always connected in parallel, NOT in series. Give two reason for connecting them in parallel.  [2]

(d) An electrical heater is rated 4 kW, 220 V. Find the cost of using this heater for 12 hours if one kWh of electrical energy costs Rs. 3.25.  [2]

(e) State one point of similarity and one point of difference between an a.c. generator and a d.c. motor. [2]

Question 4:
(a) Two isosceles right-angled glass prisms are placed near each other as shown in the figure.

Complete the path of the light ray entering the first isosceles right-angled glass prism till it emerges from the second identical prism.  [2]

(b) A certain quantity of ice at 0°C is heated till it changes into steam at 100°C. Draw a time-temperature heating curve to represent it. Label the two phase changes in your graph.  [2]

(c) What is meant by work function of a metal ?  [2]

(d) What is radioactivity ?  [2]

(e) Mention any two differences between nuclear energy and chemical energy.  [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) A stone of mass 64.0 g is thrown vertically upward from the ground with an initial speed of 20.0 ms^-1. The gravitational potential energy at the ground level is considered to he zero. Apply the principle of conservation of energy and calculate the potential energy at the maximum height attained by the
stone, (g = 10 ms^-2).  [3]

(ii) Using the same principle, state what will be the total energy of the body at its half-way point ?  [3]

(b) Define ‘joule’, the SI unit of work and establish a relationship between the SI and CGS unit of work. [3]

(c) (i) Draw a labelled diagram of a block and tackle system of pulleys with two pulleys in each block. Indicate the directions of the load, effort and tension in the string.
(ii) Write down the relation between the load and the effort of the pulley system.  [4]

Question 6:
(a) What is meant by the ‘aperture’ and ‘shutter speed’ of a camera ? How are they related ?  [3]

(b) (i) Draw a labelled ray diagram to illustrate (1) critical angle (2) total internal reflection, for a ray of light moving from one medium to another.
(ii) Write a formula to express the relationship between refractive index of the denser medium with respect to rarer medium and its critical angle for that pair of media.  [3]

(c) (i) The diagram given alongside shows a ray of light incident on an equilateral glass prism placed in minimum deviation position. Copy the diagram and complete it to show the path of the refracted ray and the emergent ray.

(ii) How are angle of incidence and angle of emergence related to each other in this position of the prism ?  [4]

Question 7:
(a) (i) What is meant by an echo ? Mention one important condition that is necessary for an echo to be heard distinctly.
(ii) Mention one important use of echo.  [3]

(b) (i) What is the name given to a cylindrical coil whose diameter is less in comparison to its length ?
(ii) If a piece of soft iron is placed inside the current carrying coil, what is the name given to the device ?
(iii) Give one use of the device named by you in (b) (ii) above.  [3]

(c) (i) Sometimes when a vehicle is driven at a particular speed, a rattling sound is heard. Explain briefly, why this happens and give the name of the phenomenon taking place.
(ii) Suggest one way by which the rattling sound could be stopped.  [4]

Question 8:
(a) (i) Why does a magnetic needle show a deflection when brought close to a current carrying conductor ?
(ii) A wire bent into a circle carries current in an anti clockwise direction. What polarity does this face of the coil exhibit ?

(b) Three resistors of 6.0 Ω, 2.0 Ω and 4.0 Ω respectively are joined together as shown in the figure.

The resistors are connected to an ammeter and to a cell of emf 6.0 V. Calculate :
(i) The effective resistance of the circuit.
(ii) The current drawn from the cell. [3]

(c) (i) How does the heat produced in a wire or a conductor depend upon the :
(1) current passing through the conductor.
(2) resistance of the conductor ?
(ii) Draw a simple sketch of a step down transformer. Label the different parts in the diagram.

Question 9:
(a) (i) Define heat capacity of a given body. What is its SI unit ?
(ii) What is the relation between heat capacity and specific heat capacity of a substance ?  [3]

(b) A linear object is placed on the axis of a lens. An image is formed by refraction in the lens. For all positions of the object on the axis of the lens, the positions of the image are always between the lens and the object.
(i) Name the lens.
(ii) Draw a ray diagram to show the formation of the image of an object placed in front of the lens at any position of your choice except infinity.  [3]

(c) A piece of ice of mass 40 g is dropped into 200 g of water at 50°C.Calculate the final temperature of water after all the ice has melted.
(specific heat capacity of water = 4200 J kg^-1 °C,
specific latent heat of fusion of ice = 336 x 103 J kg^-1)  [4]

Question 10:
(a) (i) When does the nucleus of an atom become radioactive ?
(ii) How is the radioactivity of an element affected when it undergoes a chemical change to form a chemical compound ?
(iii) Name the product of nuclear fission which is utilized to bring about further fission of 23592U.  [3]

(b) (i) Mention one use and one harmful effect of radioactivity.
(ii) Give one source of background radiation.  [3]

(c) (i)

The above diagram shows an electron gun of a hot cathode ray tube,
1. Name the parts X and Y.
2. A 6V d.c. source and a 1000V d.c. source are available. Show how these sources should be connected to the terminals of X and Y so as to obtain a focused beam of fast moving electrons.
(ii) Give one use of a cathode ray tube.  [4]

ICSE Paper 2009
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) If ‘m’ is the mass of the body, ‘v’ its velocity and ‘p’ the momentum then write a relationship between change in momentum, mass and velocity of the body
when :
(i) v is almost equal to c, the velocity of light.
(ii) v is very, very less as compared to c, the velocity of light.  [2]

(b) (i) With reference to the terms mechanical advantage, velocity ratio and efficiency of a machine, name the term that will not change for a machine of a given design.
(ii) Define the term stated by you in part (i).  [2]

(c) What is the S.I unit of energy ? How is the electron volt (eV) related to it ?  [2]

(d) State the energy changes that takes place in the following when they are in use :
(i) a photovoltaic cell.
(ii) an electromagnet.  [2]

(e) A body of mass 5 kg is moving with a velocity of 10 m s^-1. What will be the ratio of its initial kinetic energy and final kinetic energy, if the mass of the body is doubled and its velocity is halved ?  [2]

Question 2:
(a) A ray of light strikes the surface of a rectangular glass block such that the angle of incidence is (i) 0° (ii) 42°. Sketch a diagram to show the approximate path taken by the ray in each case as it passes through the glass block and emerges from it.  [2]

(b) State the conditions required for total internal reflection of light to take place.  [2]

(c) Copy and complete the following table :

Type of lens	Position of Object	Nature of Image	Size of Image
Convex	At F
Concave	At infinity

(d) (i) Why is white light considered to be polychromatic in nature ?
(ii) Give the range of the wavelength of those electromagnetic waves which are visible to us.  [2]

(e) An ultrasonic wave is sent from a ship towards the bottom of the sea. It is found that the time interval between the sending and the receiving of the wave is 1.5 second. Calculate the depth of the sea if the velocity of sound in sea water is 1400 ms^-1.  [2]

Question 3:
(a) A stringed musical instrument, such as the Sitar, is provided with a number of wires of different thicknesses. Explain the reason for this.  [2]
(b) What is meant by noise pollution ? Write the name of one source of sound that causes noise pollution.  [2]
(c) The equivalent resistance of the following circuit diagram is 4Ω. Calculate the value of x.  [2]

(d) An electric heater is rated 1000 W – 200 V. Calculate :
(i) the resistance of the heating element.
(ii) the current flowing through it.  [2]

(e) (i) Give two characteristic properties of copper wire which make it unsuitable for use as fuse wire.
(ii) Name the material which is used as a fuse wire ?   [2]

Question 4:
(a) The figure given below shows an electromagnet.

(i) What will be the polarity at the end X ?
(ii) Suggest a way by which the strength of the electromagnet referred to in the question, may be increased.  [2]

(b) Why do pieces of ice added to a drink cool it much faster than ice cold water added to it ?  [2]

(c) 40 g of water at 60°C is poured into a vessel containing 50 g of water at 20°C. The final temperature recorded is 30°C. Calculate the thermal capacity of the vessel. (Take specific heat capacity of water as 4.2 Jg^-1 °C^-1).  [2]

(d) Give two important precautions that should be taken while handling radioactive materials.  [2]

(e) (i) What is the name given to atoms of a substance which have the same atomic number but different mass numbers ?
(ii) What is the difference in the atomic structures of such atoms ?  [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) 6.4 kJ of energy causes a displacement of 64 min a body in the direction of force in 2.5 seconds. Calculate (i) the force applied (ii) power in horse power (hp). (Take 1 hp = 764 W).  [3]

(b) A pulley system comprises two pulleys, one fixed and the other movable.
(i) Draw a labelled diagram of the arrangement and show clearly the directions of all the forces acting on it.
(ii) What change can be made in the movable pulley of this system to increase
the mechanical advantage of the system.  [3]

(c) An object of mass ‘m’ is allowed to fall freely from point A as shown in the figure. Calculate the total mechanical energy of the object at:

(i) Point A
(ii) Point B
(iii) Point C
(iv) State the law which is verified by your calculations in parts (i), (ii) and (iii).  [4]

Question 6:
(a) How does the value of angle of deviation produced by a prism change with an increase in the:
(i) value of angle of incidence.
(ii) wave-length of incident light ?  [3]

(b) (i) Copy and complete the diagram to show the formation of the image of the object AB.

(ii) What is the name given to X ?  [3]

(c) (i) The diagram given alongside shows a ray of white light PQ coming from an object P and incident on the surface of a thick glass plane mirror. Copy the diagram and complete it to show the formation of three images of the object P as formed by the mirror.

(ii) Which image will be the brightest image ?  [4]

Question 7:
(a) (i) What is the principle on which sonar is based ?
(ii) Calculate the minimum distance at which a person should stand in front of a reflecting surface so that he can hear a distinct echo.
(Take speed of sound in air = 350 ms^-1).  [3]

(b) (i) Name the characteristic of sound which enables a person to differentiate between two sounds with equal loudness but having different frequencies.
(ii) Define the characteristic named by you in (i).
(iii) Name the characteristic of sound which enables a person to differentiate between two sounds of the same soundness and frequency but produced by different instruments. [3]

(c) (i) A person is tuning his radio set to a particular station. What is the person trying to do to tune it ?
(ii) Name the phenomenon involved, in tuning the radio set.
(iii) Define the phenomenon named by you in part (ii).  [4]

Question 8:
(a) (i) State Ohm’s Law.
(ii) Diagrammatically illustrate how you would connect a key, a battery, a voltmeter, an ammeter, an unknown resistance R and a rheostat so that it can be used to verify the above law.  [3]

(b) (i) Draw a neat and labelled diagram to show the structure of an a.c. generator.
(ii) State the energy conversion taking place in the generator when it is working.  [3]

(c) (i) The diagram (a) and (b) given below are of a plug and a socket with arrow marked as 1, 2, 3 and 4, 5, 6 respectively on them. Identify and write Live (L), Neutral (N) and Earth (E) against the correct number.

(ii) Calculate the electrical energy consumed when a bulb of 40 W is used for 12.5 hours everyday for 30 days.  [4]

Question 9:
(a) State in brief, the meaning of each of the following :
(i) The heat capacity of a body is 50 J °C^-1.
(ii) The specific latent heat of fusion of ice is 336000 J kg^-1.
(iii) The specific heat capacity of copper is 0.4 Jg^-1 °C^-1.  [3]

(b) (i) What is the principle of method of mixtures ?
(ii) Name the law on which this principle is based.  [3]

(c) Calculate the amount of ice which is required to cool 150 g of water contained in a vessel of mass 100 g at 30°C, such that the final temperature of the mixture is 5°C. (Take specific heat capacity of material of vessel as 0.4 Jg^-1 °C^-1, specific latent heat of fusion of ice = 336 Jg^-1, specific heat capacity of water = 4.2 Jg^-1 °C^-1).  [4]

Question 10:
(a) (i) What is meant by free electrons ?
(ii) Why are they generally not able to leave the metallic surface ?
(iii) Suggest one way by which these electrons could be made to leave the metal surface.  [3]

(b) In a cathode ray tube why is the :
(i) filament made of tungsten ?
(ii) cathode plate coated with oxide of barium or strontium ?
(iii) thick glass screen coated with barium platinocyanide ?  [3]

(c) A nucleus AZX emits an alpha particle followed by γ emission; thereafter it emits two β particles to form X₃
(i) Copy and complete the values of A and Z for X₃ :

(ii) Out of alpha (α), beta (β) and gamma (γ) radiations :
1. which radiation is the most penetrating ?
2. which radiations are negatively charged ?  [4]

 

ICSE Paper 2010
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) Name the device used for measuring :
(i) mass
(ii) weight.  [2]

(b) A body weighs 360 N on the earth :
(i) What would be his approximate weight on the moon ?
(ii) What is the reason for your answer ?  [2]

(c) A body is acted upon by a force. State two conditions under which the work done could be zero. [2]

(d) A spring is kept compressed by a small trolley of mass 0.5 kg lying on a smooth horizontal surface as shown in the figure given below :

When the trolley is released, it is found to move at a speed of 2 ms^-1. [2]

(e) Name the subjective property :
(i) of sound related to its frequency.
(ii) of light related to its wavelength. [2]

Question 2:
(a) (i) Why is the mechanical advantage of a lever of the second order always greater than one ?
(ii) Name the type of single pulley that has a mechanical advantage greater than one.  [2]

(b) (i) What is meant by refraction of light ?
(ii) What is the cause of refraction of light ?  [2]

(c) ‘The refractive index of diamond is 2.42’.
What is meant by this statement ? [2]

(d) We can bum a piece of paper by focusing the sun rays by using of lens.
(i) Name the type of lens used for the above purpose.
(ii) Draw a ray diagram to support your answer.

(e) A ray of light enters a glass slab PQRS, as shown in the diagram. The critical angle of the glass is 42°. Copy this diagram and complete the path of the ray till it emerges from the glass slab.

Mark the angles in the diagram wherever necessary.  [2]

Question 3:
(a) State two differences between light waves and sound waves.  [2]

(b) Two waves of the same pitch have their amplitudes in the ratio 2 : 3.
(i) What will be the ratio of their loudness ?
(ii) What will be the ratio of their frequencies ?  [2]

(c) Give two differences between a d.c. motor and an a.c. generator.  [2]

(d) Six resistances are connected together as shown in the figure. Calculate the equivalent resistance between the points A and B.  [2]

(e) (i) Which part of an electrical appliance is earthed ?
(ii) State a relation between electrical power, resistance and potential difference in an electrical circuit. [2]

Question 4:
(a) A device is used to transform 12V a.c. to 200 V a.c.
(i) What is the name of this device ?
(ii) Name the principle on which it works.  [2]

(b) (i) Which materials is the calorimeter commonly made of ?
(ii) Give one reason for using this material.  [2]

(c) (i) Name a metal that is used as an electron emitter.
(ii) Give one reason for using this metal.  [2]

(d) Complete the following nuclear changes:  [2]

(e) (i) Which radiation produces maximum biological damage ?
(ii) What happens to the atomic number of an element when the radiation named by you in part (i) above, are emitted ?  [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) Define the term momentum.
(ii) How is force related to the momentum of a body ?
(iii) State the condition when the change in momentum of a body depends only on the change in its velocity.  [3]

(b) A body of mass 50 kg has a momentum of 3000 kg ms^-1. Calculate :
(i) the kinetic energy of the body.
(ii) the velocity of the body.

(c) (i) Write a relation expressing the mechanical advantage of a lever.
(ii) Write an expression for the mechanical advantage of an inclined plane.
(iii) Give two reasons as to why the efficiency of a single movable pulley system is always less than 100%. [4]

Question 6:
(a) A stick partly immersed in water appears to be bent. Draw a ray diagram to show the bending of the stick when placed in water and viewed obliquely from above.  [3]

(b) A ray of monochromatic light is incident from air on a glass slab :
(i) Draw a labelled ray diagram showing the change in the path of the ray till it emerges from the glass slab.
(ii) Name the two rays that are parallel to each other.
(iii) Mark the lateral displacement in your diagram.  [3]

(c) An erect, magnified and virtual image is formed, when an object is placed between the optical centre and principal focus of a lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the formation of the image with the above stated Characteristics.  [4]

Question 7:
(a) Two parallel ray of Red and Violet travelling through air, meet the air glass boundary as shown in the given figure.

(i) Will their paths inside the glass be parallel ? Air Give a reason for your answer.
(ii) Compare the speeds of the two rays inside the glass.  [3]

(b) (i) A man stands at a distance of 68 m from a cliff and fires a gun. After what time interval will he hear the echo, if the speed of sound in air is 340 ms^-1 ?
(ii) If the man had been standing at a distance of 12 m from the cliff would he have heared a clear echo ?

(c) (i) In what unit does the domestic electric meter measure the electrical energy consumed ? State the value of this unit in S.I.
(ii) Why should switches always be connected to the live wire ?
(iii) Give one precaution that should be taken while handling switches. [4]

Question 8:
(a) Calculate the quantity of heat that will be produced in a coil of resistance 75 Ω if a current of 2A is passed through it for 2 minutes. [2]

(b) (i) A substance has nearly zero resistance at a temperature of 1 K. What is such a substance called ?
(ii) State any two factors which affect the resistance of a metallic wire. [3]

(c) Five resistors of different resistances are connected together as shown in the figure. A 12 V battery is connected to the arrangement. Calculate :

(i) the total resistance in the circuit.
(ii) the total current flowing in the circuit.

Question 9:
(a) (i) Define the term ‘specific latent heat of fusion’ of a substance.
(ii) Name the liquid which has the highest specific heat capacity.
(iii) Name two factors on which the heat absorbed or given out by a body depends. [3]

(b) (i) An equal quantity of heat is supplied to two substances A and B. The substance A shows a greater rise in temperature. What can you say about the heat capacity of A as compared to that of B ?
(ii) What energy change would you expect to take place in the molecules of a substance when it undergoes :
1. a change in its temperature ?
2. a change in its state without any change in its temperature ?  [3]

(c) 50 g of ice at 0 °C is added to 300 g of a liquid at 30 °C. What will be the final temperature of the mixture when all the ice has melted ? The specific heat capacity of the liquid is 2.65 Jg^-1 °C^-1 while that of water is 4.2 Jg^-1 °C^-1. Specific latent heat of fusion of ice = 336 Jg^-1.  [4]

Question 10:
(a) (i) Name the radioactive radiations which have the least penetrating power.
(ii) Give one use of radio isotopes.
(iii) What is meant by background radiation ? [3]

(b) (i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.

(ii) Name the law which helped you to find the direction of the magnetic field lines. [3]

(c) (i) State two ways by which the magnetic field of a solenoid can be made stronger.
(ii) What material is used for making the armature of an electric bell ? Give a reason for using this material. [4]

 

ICSE Paper 2011
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) (i) Define one newton.
(ii) Write the relation between S.I. unit and C.G.S. unit of force.  [2]

(b) Where does the position of centre of gravity lie for
(i) a circular lamina
(ii) a triangular lamina ?  [2]

(c) A man can open a nut by applying a force of 150 N by using a lever handle of length 0.4 m. What should be the length of the handle if he is able to open it by applying a force of 60 N ?  [2]

(d) Name a machine which can be used to
(i) multiply force
(ii) change the direction of force applied.  [2]

(e) The diagram below shows a lever in use.

(i) To which class of lever does it belong ?
(ii) If FA = 40 cm, AB = 60 cm, then find the mechanical advantage of the lever.  [2]

Question 2:
(a) A ball of mass 200 g falls from a height of 5 m. What will be its kinetic energy when it just reaches the ground ? (g = 9.8 ms^-2). [2]

(b) In the diagram below, PQ is a ray of light incident on a rectangular glass block.
(i) Copy the diagram and complete the path of the ray of light through the glass block. In your diagram, mark the angle of incidence by letter ‘i’ and the angle of emergence by the letter ‘e’.

(ii) How are the angle ‘i’ and ‘e’ related to each other ? [2]

(c) A ray of monochromatic light enters a liquid from air as shown in the diagram given below :
(i) Copy the diagram and show in the diagram the path of the ray of light after it strikes the mirror and re-enters the medium of air.
(ii) Mark in your diagram the two angles on the surface of separation when the ray of light moves out from the liquid to air. [2]

(d) (i) When does a ray of light falling on a lens pass through it undeviated ?
(ii) Which lens can produce a real and inverted image of an object ? [2]

(e) (i) How is the refractive index of a medium related to its real depth and apparent depth ?
(ii) Which characteristic property of light is responsible for the blue colour of the sky ? [2]

Question 3:
(a) When acoustic resonance takes place a loud sound is heard. Why does this happen ? Explain. [2]

(b) (i) Three musical instruments give out notes at the frequencies listed below.
Flute : 400 Hz; Guitar : 200 Hz; Trumpet; 500 Hz. Which one of these has the highest pitch ?
(ii) With which of the following frequencies does a tuning fork of 256 Hz resonate ? 288 Hz, 314 Hz, 333 Hz, 512 Hz. [2]

(c) Two bulbs are marked 100 W, 220 V and 60 W, 110 V. Calculate the ratio of their resistances. [2]

(d) (i) What is the colour code for the insulation on the earth wire ?
(ii) Write an expression for calculating electrical power in terms of current and resistance. [2]

(e) Calculate the equivalent resistance between A and B from the following diagram:   [2]

) Differentiate between heat and temperature.  [2]

(b) (i) Define Calorimetry.
(ii) What is meant by Energy degradation ?  [2]

(c) 200 g of hot water at 80 °C is added to 300 g of cold water at 10 °C. Calculate the final temperature of the mixture of water. Consider the heat taken by the container to be negligible, [specific heat capacity of water is 4200 J kg^-1 °C^-1]  [2]

(d) Fill in the blanks in the following sentences with appropriate words :
(i) During the emission of a beta particle, the ………. number remains the same.
(ii) The minimum amount of energy required to emit an electron from a metal surface is called ………. .  [2]

(e) A mixture of radioactive substances gives off three types of radiations.
(i) Name the radiation which travels with the speed of light.
(ii) Name the radiation which has the highest ionizing power. [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) What is meant by an ideal machine ?
(ii) Write a relationship between the mechanical advantage (M.A.) and velocity ratio (V.R.) of an ideal machine.
(iii) A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why. [3]

(b) Draw a diagram to show the energy changes in an oscillating simple pendulum.
Indicate in your diagram how the total mechanical energy in it remains constant during the oscillation.     [3]

(c) A uniform metre scale can be balanced at the 70.0 cm mark when a mass of 0.05 kg is hung from the 94.0 cm mark.
(i) Draw a diagram of the arrangement.
(ii) Find the mass of the metre scale. [4]

Question 6:
(a) (i) State the laws of refraction of light.
(ii) Write a relation between the angle of incidence (i), angle of emergence (e), angle of prism (A) and angle of deviation (d) for a ray of light passing through an equilateral prism.  [3]

(b) (i) Suggest one way, in each case, by which we can detect the presence of:
(1) Infrared radiations (2) Ultraviolet radiations.
(ii) Give one use of Infrared radiations.  [3]

(c) An object is placed in front of a lens between its optical centre and the focus and forms a virtual, erect and diminished image.
(i) Name the lens which formed this image.
(ii) Draw a ray diagram to show the formation of the image with the above stated characteristics.  [4]

Question 7:
(a) (i) Name the type of waves which are used for sound ranging.
(ii) Why are these waves mentioned in (i) above, not audible to us ?
(iii) Give one use of sound ranging.  [3]

(b) A man standing 25 m away from a wall produces a sound and receives the reflected sound.
(i) Calculate the time after which he receives the reflected sound if the speed of sound in air is 350 ms^-1.
(ii) Will the man be able to hear a distinct echo ? Give a reason for your answer. [3]

(c) (i) Name two safety devices which are connected to the live wire of a household electrical circuit.
(ii) Give one important function of each of these two devices. [4]

Question 8:
(a) (i) Draw a graph of Potential difference (V) versus Current (I) for an ohmic resistor.
(ii) How can you find the resistance of the resistor from this graph ?
(iii) What is a non-ohmic resistor ? [3]

(b) (i) An electric bulb is marked 100 W, 250 V. What information does this convey ?
(ii) How much current will the bulb draw if connected to a 250 V supply ? [3]

(c) Three resistors are connected to a 12 V battery as shown in the figure given below:

(i) What is the current through the 8 ohm resistor ?
(ii) What is the potential difference across the parallel combination of 6 ohm and 12 ohm resistor ?
(iii) What is the current through the 6 ohm resistor ?

Question 9:
(a) (i) Explain why the weather becomes very cold after a hail storm.
(ii) What happens to the heat supplied to a substance when the heat supplied causes no change in the temperature of the substance ?  [3]

(b) (i) When 1 g of ice at 0 °C melts to form lg of water at 0 °C then, is the latent heat absorbed by the ice or given out by it ?
(ii) Give one example where high specific heat capacity of water is used as a heat reservoir.
(iii) Give one example where high specific heat capacity of water is used for cooling purposes. [3]

(c) 250 g of water at 30 °C is present in a copper vessel of mass 50 g. Calculate the mass of ice required to bring down the temperature of the vessel and its contents to 5 °C.
Specific latent heat of fusion of ice = 336 x 10³ J kg^-1.
Specific heat capacity of copper vessel = 400 J kg^-1 °C^-1.
Specific heat capacity of water = 4200 J kg^-1 °C^-1.   [4]

Question 10:
(a) (i) State two properties which a substance should possess when used as a thermionic emitter.
(ii) When an alpha particle gains two electrons it becomes neutral and becomes an atom of an element which is a rare gas. What is the name of this rare gas ?  [3]

(b) (i) Define radioactivity.
(ii) What happens inside the nucleus that causes the emission of beta particle ?
(iii) Express the above change in the form of an equation.  [3]

(c) (i) Name a device which is commonly used to convert an electrical signal into a visual signal.
(ii) The nucleus 20284X emits an alpha particle and forms the nucleus Y. Represent this change in the form of an equation.
(iii) What changes will take place in the mass number and atomic number of the nucleus Y if it emits gamma radiations ?  [4]

 

ICSE Paper 2012
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) (i) Define 1 kgf.
(ii) How is it related to the S.I unit of force ? [2]
(b) (i) What are non-contact forces ?
(ii) How does the distance of separation between two bodies affect the magnitude of the non-contact force between them ? [2]
(c) A boy of mass 30 kg is sitting at a distance of 2m from the middle of a see-saw. Where should a boy of mass 40 kg sit so as to balance the see-saw ? [2]
(d) (i) What is meant by the term ‘moment of force’ ?
(ii) If the moment of force is assigned a negative sign then will the turning tendency of the force be clockwise or anticlockwise ? [2]
(e) A ball is placed on a compressed spring. When the spring is released, the ball is observed to fly away.

(i) What form of energy does the compressed spring possess ?
(ii) Why does the ball fly away ? [2]

Question 2:
(a) (i) State the energy conversion taking place in a solar cell.
(ii) Give one disadvantage of using a solar cell. [2]
(b) A body of mass 0.2 kg falls from a height of 10m to a height of 6m above the ground. Find the loss in potential energy taking place in the body, [g = 10 ms^-2]  [2]
(c) (i) Define the term refractive index of a medium in terms of velocity of light.
(ii) A ray of light moves from rare medium to a dense medium as shown in diagram below. Write down the number of the ray which represents the partially reflected ray. [2]

(d) You are provided with a printed piece of paper. Using this paper how will you differentiate between a convex lens and a concave lens ? [2]
(e) A ray of light incident at an angle of incidence V passes through an equilateral glass prism such that the refracted ray inside the prism is parallel to its base and emerges from the prism at an angle of emergence ‘e’.
(i) How is the angle of emergence ‘e’ related to the angle of incidence ‘i’ ?
(ii) What can you say about the value of the angle of deviation in such a situation ? [2]

Question 3:
(a) (i) What is meant by ‘Dispersion of light’ ?
(ii) In the atmosphere which colour of light gets scattered the least ? [2]
(b) Which characteristic of sound will change if there is a change in
(i) its amplitude.
(ii) its waveform. [2]
(c) (i) Name one factor which affects the frequency of sound emitted due to vibrations in an air column.
(ii) Name the unit used for measuring the sound level. [2]
(d) An electrical appliance is rated at 1000 KVA, 220V. If the appliance is operated for 2 hours, calculate the energy consumed by the appliance in :
(i) kWh         (ii) joule   [2]
(e) Calculate the equivalent resistance between P and Q from the following diagram: [2]

Question 4:
(a) (i) What is an a.c. generator or Dynamo used for ?
(ii) Name the principle on which it works. [2]
(b) Differentiate between heat capacity and specific heat capacity. [2]
(c) A hot solid of mass 60g at 100°C is placed in 150 g of water at 20°C. The final steady temperature recorded is 25°C. Calculate the specific heat capacity of the solid. [Specific heat capacity of water = 4200 J kg^-1 °C^-1]  [2]
(d) (i) What is the value of the speed of gamma radiations in air or vacuum ?
(ii) Name a material which exhibits fluorescence when cathode rays fall on it. [2]
(e) Give any two important sources of background radiation. [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) Which of the following remains constant in uniform circular motion : Speed or Velocity or both ?
(ii) Name the force required for uniform circular motion. State its direction. [3]
(b) (i) State the class of levers and the relative positions of load (L), effort (E) and fulcrum (F) in each of the following cases :
1. A bottle opener.
2. Sugar tongs.
(ii) Why is less effort needed to lift a load over an inclined plane as compared to lifting the load directly ?                                                                                                                                                                          [3]
(c) (i) A moving body weighing 400 N possesses 500 J of kinetic energy. Calculate the velocity with which the body is moving. (g = 10 ms^-2)
(ii) Under what condition will a set of gears produce :
1. a gain in speed.
2. a gain in torque. [4]

Question 6:
(a) (i) What is meant by the term ‘critical angle’ ?
(ii) How is it related to the refractive index of the medium ?
(iii) Does the depth of a tank of water appear to change or remain the same when viewed normally from above ?
(b) A ray of light PQ is incident normally on the hypotenuse of a A right angled prism ABC as shown in the diagram given below:

(i) Copy the diagram and complete the path of the ray PQ till it emerges from the prism.
(ii) What is the value of the angle of deviation of the ray ? B
(iii) Name an instrument where this action of the prism is used. [3]
(c) A converging lens is used to obtain an image of an object placed in front of it. The inverted image is formed between F₂ and 2F₂ of the lens.
(i) Where is the object placed ?
(ii) Draw a ray diagram to illustrate the formation of the image obtained. [4]

Question 7:
(a) (i) What is meant by Resonance ?
(ii) State two ways in which Resonance differs from Forced vibrations. [3]
(b) (i) A man standing between two cliffs produces a sound and hears two successive echoes at intervals of 3s and 4s respectively. Calculate the distance between the two cliffs.
The speed of sound in the air is 330 ms^-1.
(ii) Why will an echo not be heard when the distance between the source of sound and the reflecting surface is 10 m? [3]
(c) The diagram below shows the displacement-time graph for a vibrating body.

(i) Name the type of vibrations produced by the vibrating body.
(ii) Give one example of a body producing such vibrations.
(iii) Why is the amplitude of the wave gradually decreasing ?
(iv) What will happen to the vibrations of the body after some time ? [4]

Question 8:
(a) (i) A cell is sending current in an external circuit. How does the terminal voltage compare with the e.m.f. of the cell ?
(ii) What is the purpose of using a fuse in an electrical circuit ?
(iii) What are the characteristic properties of fuse wire ? [3]
(b) (i) Write an expression for the electrical energy spent in the flow of current through an electrical appliance in terms of I, R and t.
(ii) At what voltage is the alternating current supplied to our houses ?
(iii) How should the electric lamps in a building be connected ? [3]
(c) Three resistors are connected to a 6V battery as shown in the figure given below:

Calculate:
(i) the equivalent resistance of the circuit.
(ii) total current in the circuit.
(iii) potential difference across the 7.2 Ω resistor.

Question 9:
(a) (i) Write an expression for the heat energy liberated by a hot body.
(ii) Some heat is provided to a body to raise its temperature by 25°C. What will be the corresponding rise in temperature of the body as shown on the kelvin scale ?
(iii) What happens to the average kinetic energy of the molecules as ice melts at 0°C ? [3]
(b) A piece of ice at 0°C is heated at a constant rate and its temperature recorded at regular intervals till steam is formed at 100°C. Draw a temperature – time graph to represent the change in phase Label the different parts of your graph. [3]
(c) 40g of ice at 0°C is used to bring down the temperature of a certain mass of water at 60°C to 10°C. Find the mass of water used.
[Specific heat capacity of water = 4200 J kg^-1 °C^-1.]
[Specific latent heat of fusion of ice – 336 x 103 J kg^-1.]  [4]

Question 10:
(a) The diagram below shows a current carrying loop or a circular coil passing through d’sheet of cardboard at the points M and N. The sheet of cardboard is sprinkled uni formly with iron filings.

(i) Copy the diagram and draw an arrow on the circular coil to show the direction of current flowing through it.
(ii) Draw the pattern of arrangement of the iron filings when current is passed through the loop. [3]
(b) (i) Draw a simplified labelled diagram of a hot cathode ray tube.
(ii) Name a common device where a hot cathode ray tube is used. [3]
(c) A certain nucleus X has a mass number 14 and atomic number 6. The nucleus X changes to ₇Y¹⁴ after the loss of a particle.
(i) Name the particle emitted.
(ii) Represent this change in the form of an equation.
(iii) A radioactive substance is oxidized. What change would you expect to take place in the nature of its radioactivity ? Give a reason for your answer. [4]

 

ICSE Paper 2013
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section.

Question 1:
(a) Give any two effects of a force on a non-rigid body. [2]
(b) One end of a spring is kept fixed while the other end is stretched by a force as shown in the diagram.

(i) Copy the diagram and mark on it the direction of the restoring force.
(ii) Name one instrument which works on the above principle. [2]
(c) (i) Where is the centre of gravity of a uniform ring situated ?
(ii) “The position of the centre of gravity of a body remains unchanged even when the body is deformed.” State whether the statement is true or false. [2]
(d) A force is applied on a body of mass 20 kg moving with a velocity of 40 ms^-1. The body attains a velocity of 50 ms^-1 in 2 seconds. Calculate the work done by the body. [2]
(e) A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage.
(i) Name the type of pulley used.
(ii) For what purpose is such a pulley used ? [2]

Question 2:
(a) (i) In what way does an ‘Ideal machine’ differ from a ‘Practical machine’ ?
(ii) Can a simple machine act as a force multiplier and a speed multiplier at the same time ? [2]
(b) A girl of mass 35 kg climbs up from the first floor of a building at a height 4m above the ground to the third floor at a height 12m above the ground. What will be the increase in her gravitational potential energy ? (g = 10 ms^-2). [2]
(c) Which class of lever found in the human body is being used by a boy :
(i) When he holds a load on the palm of his hand.
(ii) When he raises the weight of his body on his toes ? [2]
(d) A ray of light is moving from a rarer medium to a denser medium and strikes a plane mirror placed at 90° to the direction of the ray as shown in the diagram.

(i) Copy the diagram and mark arrows to show the path of the ray of light after it is reflected from the mirror.
(ii) Name the principle you have used to mark the arrow to show the direction of the ray. [2]
(e) (i) The refractive index of glass with respect to air is 1.5. What is the value of the refractive index of air with respect to glass ?
(ii) A ray of light is incident as a normal ray on the surface of separation of two different mediums. What is the value of the angle of incidence in this case ? [2]

Question 3:
(a) A bucket kept under a running tap is getting filled with water. A person sitting at a distance is able to get an idea when the bucket is about to be filled.
(i) What change takes place in the sound to give this idea ?
(ii) What causes the change in the sound ? [2]
(b) A sound made on the surface of a lake takes 3s to reach a boatman. How much time will it take to reach a diver inside the water at the same depth ?
Velocity of sound in air = 330 ms^-1
Velocity of sound in water = 1450 ms^-1. [2]
(c) Calculate the equivalent resistance between the points A and B for the following combination of resistors: [2]

(d) You have been provided with a solenoid AB.

(i) What is the polarity at end A ?
(ii) Give one advantage of an electromagnet over a permanent magnet. [2]
(e) (i) Name the device used to protect the electric circuits from overloading and short circuits.
(ii) On what effect of electricity does the above device work ? [2]

Question 4:
(a) Define the term ‘Heat capacity’ and state its S.I. unit. [2]
(b) What is meant by Global warming ? [2]
(c) How much heat energy is released when 5g of water at 20 C changes to ice at 0°C ?
[Specific heat capacity of water = 4.2 Jg^-1 °C^-1.
Specific latent heat of fusion of ice = 336 Jg^-1] [2]
(d) Which of the radioactive radiations :
(i) Can cause severe genetical disorders.
(ii) Are deflected by an electric field ? [2]

(e) A radioactive nucleus undergoes a series of decays according to the sequence

If the mass number and atomic number of X₃ are 172 and 69 respectively, what is the mass number and atomic number of X ? [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) With reference to their direction of action, how does a centripetal force differ from a centrifugal force ?
(ii) State the Principle of conservation of energy.
(iii) Name the form of energy which a body may possess even when it is not in motion. [3]
(b) A coolie is pushing a box weighing 1500 N up an inclined plane 7.5m long on to a platform, 2.5m above the ground.
(i) Calculate the mechanical advantage of the inclined plane.
(ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort. [3]
(c) A block and tackle system of pulleys has a velocity ratio 4.
(i) Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
(ii) What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system ? [4]

Question 6:
(a) Name the radiations:
(i) That are used for photography at night.
(ii) Used for detection of fracture in bones.
(iii) Whose wavelength range is from 100 A to 4000 A (or 10 nm to 400 nm). [3]
(b) (i) Can the absolute refractive index of a medium be less than one ?
(ii) A coin placed at the bottom of a beaker appears to be raised by 4.0 cm. If the refractive index of water is 4/3, find the depth of the water in the beaker. [3]
(c) An object AB is placed between 2F₁ and F₁ on the principal axis of a convex lens as shown in the diagram.

Copy the diagram and using three rays starting from point A, obtain the image of the object formed by the lens. [4]

Question 7:
(a) (i) What is the principle on which SONAR is based ?
(ii) An observer stands at a certain distance away from a cliff and produces a loud sound. He hears the echo of the sound after 1.8s. Calculate the distance between the cliff and the observer if the velocity of sound in air is 340 ms. [3]
(b) A vibrating tuning fork is placed over the mouth of a burette filled with water. The tap of the burette is opened and the water level gradually starts falling. It is found that the sound from the tuning fork becomes very loud for a particular length of the water column.
(i) Name the phenomenon taking place when this happens.
(ii) Why does the sound become very loud for this length of the water column ? [3]
(c) (i) What is meant by the terms (1) amplitude (2) frequency, of a wave ?
(ii) Explain why stringed musical instruments, like the guitar, are provided with a hollow box. [4]

Question 8:
(a) (i) It is observed that the temperature of the surroundings starts falling when the ice in a frozen lake starts melting. Give a reason for the observation.
(ii) How is the heat capacity of the body related to its specific heat capacity ? [3]

(b) (i) Why does a bottle of soft drink cool faster when surrounded by ice cubes than by ice cold water, both at 0 °C ?
(ii) A certain amount of heat Q will warm lg of material X by 3 °C and 1 g of material Y by 4 °C. Which material has a higher specific heat capacity ? [3]
(c) A calorimeter of mass 50g and specific heat capacity 0.42 Jg^-1 °C^-1 contains some mass of water at 20°C. A metal piece of mass 20g at 100 °C is dropped into the calorimeter. After stirring, the final temperature of the mixture is found to be 22 °C. Find the mass of water used in the calorimeter.
[specific heat capacity of the metal piece = 0.3 Jg^-1 °C^-1
specific heat capacity of water = 4.2 Jg^-1 °C^-1]  [4]

Question 9:
(a) (i) State Ohm’s law.
(ii) A metal wire of resistance 6Ω is stretched so that its length is increased to twice its original length. Calculate its new resistance. [3]
(b) (i) An electrical gadget can give an electric shock to its user under certain circumstances. Mention any two of these circumstances.
(ii) What preventive measure provided in a gadget can protect a person from an electric shock ? [3]
(c) The figure shows a circuit

When the circuit is switched on, the ammeter reads 0.5 A.
(i) Calculate the value of the unknown resistor R.
(ii) Calculate the charge passing through the 3Ω resistor in 120 s.
(iii) Calculate the power dissipated in the 3Ω resistor. [4]

Question 10:
(a) Name the three main parts of a Cathode Ray Tube. [3]
(b) (i) What is meant by Radioactivity ?
(ii) What is meant by nuclear waste ?
(iii) Suggest one effective way for the safe disposal of nuclear waste. [3]

(c) (i) Draw a simple labelled diagram of a d.c. electric motor.
(ii) What is the function of the split rings in a d.c. motor ?
(iii) State one advantage of a.c. over d.c. [4]

 

ICSE Paper 2014
Physics

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

SECTION-I (40 Marks)

Attempt all questions from this Section

Question 1:
(a) A force is applied on (i) a non-rigid body and (ii) a rigid body. How does the effect of the force differ in the above two cases ? [2]
(b) A metallic ball is hanging by a string from a fixed support. Draw a neat labelled diagram showing the forces acting on the bail and the string. [2]
(c) (i) What is the weight of a body placed at the centre of the earth ?
(ii) What is the principle of an ideal machine ? [2]
(d) Is it possible to have an accelerated motion with a constant speed ? Explain. [2]
(e) (i) When does a force do work ?
(ii) What is the work done by the moon when it revolves around the earth ? [2]

Question 2:
(a) Calculate the change in the Kinetic energy of a moving body if its velocity is reduced to 113rd of the initial velocity. [2]
(b) State the energy changes in the following devices while in use:
(i) A loud speaker.
(ii) A glowing electric bulb. [2]
(c) (i) What is nuclear energy ?
(ii) Name the process used for producing electricity using nuclear energy. [2]
(d) State one important advantage and disadvantage each, of using nuclear energy for producing electricity. [2]
(e) (i) The conversion of part of the energy into an undesirable form is called ………. .
(ii) For a given height h, ………… the length l of the inclined plane, lesser will be the effort required. [2]

Question 3:
(a) Draw the diagram given below and clearly show the path taken by the emergent ray. [2]

(b) (i) What is consumed using different electrical appliances, for which electricity bills are paid ?
(ii) Name a common device that uses electromagnets. [2]
(c) (i) A ray of light passes from water to air. How does the speed of light change ?
(ii) Which colour of light travels fastest in any medium except air ? [2]
(d) Name the factors affecting the critical angle for the pair of media. [2]
(e) (i) Name a prism required for obtaining a spectrum of Ultraviolet light.
(ii) Name the radiations which can be detected by a thermopile. [2]

Question 4:
(a) Why is the colour red used as a sign of danger ? [2]
(b) (i) What are mechanical waves ?
(ii) Name one property of waves that do not change when the wave passes from one medium to another. [2]
(c) Find the equivalent resistance between points A and B. [2]

(d) 50g of metal piece at 27 °C requires 2400 J of heat energy so as to attain a temperature of 327 °C. Calculate the specific heat capacity of the metal. [2]
(e) An electron emitter must have ……….. work function and ………… melting point. [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section.

Question 5:
(a) (i) A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road. Who does more work against the force of gravity and why ?
(ii) Two forces each of 5N act vertically upwards and downwards respectively on the two ends of a uniform metre rule which is placed at its mid-point as shown in the diagram. Determine the magnitude of the resultant moment of these forces about the midpoint. [4]

(b) (i) A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy as its velocity becomes zero ?
(ii) Draw a diagram to show how a single pulley can be used so as to have its ideal M.A = 2. [3]
(c) Derive a relationship between mechanical advantages, velocity ratio and efficiency of a machine. [3]

Question 6:
(a) (i) Light passes through a rectangular glass slab and through a triangular glass prism. In what way does the direction of the two emergent beams differ and why ?
(ii) Ranbir claims to have obtained an image twice the size of the object with a concave lens. Is he correct ? Give a reason for your answer. [4]
(b) A lens forms an erect, magnified and virtual image of an object.
(i) Name the lens.
(ii) Draw a labelled ray diagram to show the image formation. [3]
(c) (i) Define the power of a lens.
(ii) The lens mentioned in 6(b) above is of focal length 25 cm. Calculate the power of the lens. [3]

Question 7:
(a) The adjacent diagram shows three different modes of vibrations P, Q and R of the same string.

(i) Which vibrations will produce a louder sound and why ?
(ii) The sound of which string will have maximum shrillness ?
(iii) State the ratio of wavelengths of P and R. [4]
(b) A type of electromagnetic wave has wavelength 50 Å.
(i) Name the wave.
(ii) What is the speed of the wave in vacuum ?
(iii) State one use of this type of wave. [3]
(c) (i) State one important property of waves used for echo depth sounding.
(ii) A radar sends a signal to an aircraft at a distance of 30 km away and receives it back after 2 x 10^-4 second. What is the speed of the signal ? [4]

Question 8:
(a) Two resistors of 4Ω and 6Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
(i) Draw a labelled circuit diagram showing the above arrangement.
(ii) Calculate the current in each resistor. [4]
(b) (i) What is an Ohmic resistor ?
(ii) Two copper wires are of the same length, but one is thicker than the other.
(1) Which wire will have more resistance ?
(2) Which wire will have more specific resistance ?  [3]
(c) (i) Two sets A and B, of the three bulbs each, are glowing in two separate rooms. When one of the bulbs in set A is fused, the other two bulbs also cease to glow. But in set B, when one bulb fuses, the other two bulbs continue to glow. Explain why this phenomenon occurs.
(ii) Why do we prefer arrangements of Set B for house circuiting ? [3]

Question 9:
(a) Heat energy is supplied at a constant rate to 100g of ice at 0 °C. The ice is converted into water at 0°C in 2 minutes. How much time will be required to raise the temperature of water from 0 °C to 20 °C ? [Given : sp. heat capacity of water = 4.2 Jg^–1 °C^–1, sp. latent heat of ice = 336 Jg^–1]. [4]
(b) Specific heat capacity of substance A is 3.8 Jg^–1 °K^–1 whereas the Specific heat capacity of substance B is 0.4 Jg^–1 °K^–1.
(i) Which of the two is a good conductor of heat ?
(ii) How is one led to the above conclusion ?
(iii) If substances A and B are liquids then which one would be more useful in car radiators ? [3]
(c) (i) State any two measures to minimize the impact of global warming.
(ii) What is the Greenhouse effect ? [3]

Question 10:
(a) (i) Name two factors on which the magnitude of an induced e.m.f. in the secondary coil depends.
(ii) In the following diagram an arrow shows the motion of the coil towards the bar magnet.
(1) State in which direction the current flows, A to B or B to A?
(2) Name the law used to come to the conclusion. [4]

(b) A nucleus ₁₁Na²⁴ emits a beta particle to change into Magnesium (Mg)
(i) Write the symbolic equation for the process.
(ii) What are numbers 24 and 11 called ? [3]
(iii) What is the general name of ₁₂Mg²⁴ with respect to ₁₁Na²⁴ ?
(c) In a cathode ray tube state :
(i) The purpose of covering cathode by thorium and carbon.
(ii) The purpose of the fluorescent screen.
(iii) How is it possible to increase the rate of emission of electrons. [3]

 

ICSE Paper 2015
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

Question 1:
(a) When a body is placed on a table top, it exerts a force equal to its weight downwards on the table top but does not move or fall.

(i) Name the force exerted by the table top.
(ii) What is the direction of the force ?  [2]
(b) (i) Name one factor that affects the lateral displacement of light as it passes through a rectangular glass slab.
(ii) On reversing the direction of the current in a wire, the magnetic field produced by it gets ………. .  [2]
(c) (i) On what factor does the position of the centre of gravity of a body depend ?
(ii) What is the S.I. unit of the moment of force ?  [2]
(d) Name the factors affecting the turning effect of a body.  [2]
(e) (i) Define equilibrium.
(ii) In a beam balance when the beam is balanced in a horizontal position, it is in ……….. equilibrium. [2]

Question 2:
(a) How is work done by a force measured when the force :
(i) is in the direction of displacement.
(ii) is at an angle to the direction of displacement.  [2]
(b) State the energy changes in the following while in use :
(i) Burning of a candle.
(ii) A steam engine.  [2]
(c) (i) A scissor is a ………… multiplier.
(ii) 1 kWh = ……….. J.  [2]
(d) Explain the motion of a planet around the sun in a circular path.  [2]
(e) Rajan exerts a force of 150 N in pulling a cart at a constant speed of 10 m/s. Calculate the power exerted.  [2]

Question 3:
(a) (i) Give the expression for mechanical advantage of an inclined plane in terms of the length of an inclined plane.
(ii) Name a common device where a gear train is used.  [2]
(b) The speed of light in glass is 2 × 10⁶ km/s. What is the refractive index of glass ?  [2]
(c) (i) Draw a graph between displacement and the time for a body executing free vibrations.
(ii) Where can a body execute free vibrations ?  [2]
(d) (i) What happens to the resistivity of semi-conductors with the increase of temperature ?
(ii) For a fuse, higher the current rating is the fuse wire.  [2]
(e) (i) Name the high energetic invisible electromagnetic waves which help in the study of the structure of crystals.
(ii) State an additional use of the waves mentioned in part (e) (i).  [2]

Question 4:
(a) Rishi is surprised when he sees water boiling at 115°C in a container. Give reasons as to why water can boil at the above temperature. [2]
(b) (i) Why does a current carrying, freely suspended solenoid rest along a particular direction ?
(ii) State the direction in which it rests. [2]
(c) Find the equivalent resistance between points A and B. [2]

(d) Give two similarities between an A.C. generator and a D.C. motor. [2]
(e) (i) Why is a cathode ray tube evacuated to a low pressure ?
(ii) What happens if the negative potential is changed on a grid ?  [2]

SECTION-II (40 Marks)

Attempt any four questions from this Section

Question 5:
(a) Draw a simplified diagram of a lemon crusher, indicating direction of load and effort. [2]
(b) (i) Name the physical quantity measured in terms of horse power.
(ii) A nut is opened by a wrench of length 20cm. If the least force required is 2N, find the moment of force needed to loosen the nut.
(iii) Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative. [4]
(c) A block and tackle system has V.R = 5.
(i) Draw a neat labelled diagram of a system indicating the direction of its load and effort.
(ii) Rohan exerts a pull of 150 Kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75% ?  [4]

Question 6:
(a) (i) Where should an object be placed so that a real and inverted image of the same size as the object is obtained using a convex lens ?
(ii) Draw a ray diagram to show the formation of the image as specified in the part a (i).  [4]
(b) (i) Why does the Sun appear red at sunrise ?
(ii) Name the subjective property of light related to its wavelength. [3]
(c) Jatin puts a pencil into a glass container having water and is surprised to see the pencil in a different state.
(i) What change is observed in the appearance of the pencil ?
(ii) Name the phenomenon responsible for the change.
(iii) Draw a ray diagram showing how the eye sees the pencil. [3]

Question 7:
(a) (i) State the safe limit of sound level in terms of decibel for human hearing.
(ii) Name the characteristic of sound in relation to its waveform. [2]
(b) A person standing between two vertical cliffs and 480 m from the nearest cliff shouts. He hears the first echo after 3s and the second echo 2s later.
Calculate:
(i) The speed of sound.
(ii) The distance of the other cliff from the person. [3]
(c) In the diagram below, A, B, C, D are four pendulums suspended from the same elastic string PQ. The length of A and C are equal to each other while the length of pendulum B is smaller than that of D. Pendulum A is set into a mode of vibrations.

(i) Name the type of vibrations taking place in pendulums B and D ?
(ii) What is the state of pendulum C ?
(iii) State the reason for the type of vibrations in pendulums B and C. [5]

Question 8:
(a) (i) Name the device used to increase the voltage at a generating station.
(ii) At what frequency is A.C. supplied to residential houses ?
(iii) Name the wire in a household electrical circuit to which the switch is connected. [3]
(b) The relationship between the potential difference and the current in a conductor is stated in the form of a law.
(i) Name the law.
(ii) What does the slope of V-I graph for a conductor represent ?
(iii) Name the material used for making the connecting wire. [3]
(c) A cell of Emf 2V and internal resistance 1.2Ω is connected with an ammeter of resistance 0.8Ω and two resistors of 4.5Ω and 9Ω as shown in the diagram below :

(i) What would be the reading on the Ammeter ?
(ii) What is the potential difference across the terminals of the cell ? [4]

Question 9:
(a) (i) Name a gas caused by the Greenhouse effect.
(ii) Which property of water makes it an effective coolant ? [2]
(b) (i) Water in lakes and ponds do not freeze at once in cold countries. Give a reason in support of your answer.
(ii) What is the principle of Calorimetry ?
(iii) Name the law on which this principle is based.
(iv) State the effect of an increase of impurities on the melting point of ice. [4]
(c) A refrigerator converts 100g of water at 20°C to ice at -10°C in 35 minutes. Calculate the average rate of heat extraction in terms of watts.
Given : Specific heat capacity of ice = 2.1 Jg^–1 °C^–1.
Specific heat capacity of water = 4.2 Jg^–1 °C^–1.
Specific Latent heat of fusion of ice = 336 Jg^–1. [4]

Question 10:
(a) (i) What is thermionic emission ?
(ii) Name the unit in which the work function of a metal is expressed. [2]
(b) (i) Complete the diagram as given alongside by drawing the deflection of radioactive radiations in an electric field.

(ii) State any two precautions to be taken while handling radioactive substances. [5]
(c) An atomic nucleus A is composed of 84 protons and 128 neutrons.
(i) The nucleus A emits an alpha particle and is transformed into nucleus B. What is the composition of nucleus B ?
(ii) The nucleus B emits a beta particle and is transformed into a nucleus C. What is the composition of nucleus C ?
(iii) Does the composition of nucleus C change if it emits gamma radiations ? [3]

ICSE Paper 2016
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

Question 1:
(a) (i) Give an example of a non contact force which is always of attractive nature.
(ii) How does the magnitude of this non contact force on the two bodies depend on the distance of separation between them? [2] 
(b) A boy weighing 4okgf climbs up a stair of 30 steps each 20 cm high in 4 minute and a girl weighing 3okgf does the same in 3 minutes. Compare:
(i) The work done by them.
(ii) The power developed by them. [2]
(c) With reference to the terms Mechanical Advantage, Velocity Ratio and efficiency of a machine, name and define the term that will not change for a machine of a given design. [2]
(d) Calculate the mass of ice required to lower the temperature of 300g of water at 40°C to water at 0°C. [2]
(Specific latent heat of we = 336 J/g, Specific heat capacity of water = 4.2 J/g°C)
(e) What do you understand by the following statements: [2]
(i) The heat capacity of the body is 60 JK^-1.
(ii) The specific heat capacity of lead is 130 Jkg^-1 K^-1.

Question 2:
(a) State two factors upon which the heat absorbed by a body depends. [2]
(b) A boy uses blue colour of light to find the refractive index of glass. He then repeats the experiment using red colour of light. Will the refractive index be the same or different in the two cases ? Give a reason to support your answer. [2]
(c) Copy the diagram given below and complete the path of light ray till it emerges out of the prism. The critical angle of glass is 42°. In your diagram mark the angles wherever necessary. [2]

(d) State the dependence of angle of deviation :
(i) On the refractive index of the material of the prism.
(ii) On the wavelength of light. [2]
(e) The ratio of amplitude of two waves is 3 :4. What is the ratio of their :
(i) loudness ? (ii) frequencies ? [2]

Question 3:
(a) State two ways by which the frequency of transverse vibrations of a stretched string can be increased.[2]
(b) What is meant by noise pollution ? Name one source of sound causing noise pollution. [2]
(c) The V-I graph for a series combination and for a parallel combination of two resistors is shown in the figure below.

Which of the two A or B, represents the parallel combination ? Give a reason for your answer. [2]
(d) A music system draws a current of 400 mA when connected to a 12V battery.
(i) What is the resistance of the music system ?
(ii) The music system is left playing for several hours and finally the battery voltage drops and the music system stops playing when the current drops to 320 mA. At what battery voltage does the music system stop playing ? [2]
(e) Calculate the quantity of heat produced in a 20Ω resistor carrying 2.5A current in 5 minutes. [2]

Question 4:
(a) State the characteristics required of a good thermion emitter. [2]
(b) An element _ZS^A decays to ₈₅R²²² after emitting 2α particles and If particle. Find the atomic number and atomic mass of the element S. [2]
(c) A radioactive substance is oxidized. Will there be any change in a nature of its radioactivity ? Give a reason for your answer. [2]
(d) State the characteristics required in a material to be used as an effective fuse wire. [2]
(e) Which coil of a step up transformer is made thicker and why ? [2]

SECTION-II (40 Marks)

(Attempt any four questions from this Section)

Question 5:
(a) A stone of mass ‘m’ is rotated in a circular path with a uniform speed by tying a strong string with the help of your hand. Answer the following questions :
(i) Is the stone moving with a uniform or variable speed ?
(ii) Is the stone moving with a uniform acceleration ? In which direction does the acceleration act ?
(iii) What kind of force acts on the hand and state its direction ? [3]

(b) From the diagram given below, answer the questions that follow :
(i) What kind of pulleys are A and B ?
(ii) State the purpose of pulley B.
(iii) What effort has to be applied at C to just raise the load L = 20 kgf ? [3]
(Neglect the weight of pulley A and friction).
(c) (i) An effort is applied on the bigger wheel of a gear having 32 teeth. It is used to turn a wheel of 8 teeth. Where is it used ?
(ii) A pulley system has three pulleys. A load of 120N is overcome by applying an effort of 50N. Calculate the Mechanical Advantage and Efficiency of this system. [4]

Question 6:
(a) (i) What is the principle of method of mixtures ?
(ii) What is the other name given to it ?
(iii) Name the law on which the principle is based. [3]
(b) Some ice is heated at a constant rate, and its temperature is recorded after every few seconds, till steam is formed at 100°C. Draw a temperature time graph to represent the change. Label the two phase changestnurgraph. [3]
(c) A copper vessel of mass 100g contains 150 g of water at 50°C. How much ice is needed to cool it to 5°C ? [4]
Given: Specific heat capacity of copper = 0.4 Jg^–1 °C^–1
Specific heat capacity of water = 4.2 Jg^–1 °C^–1
Specific latent heat of fusion of ice = 336 Jg^–1

Question 7:
(a) (i) Write a relationship between angle of incidence and angle of refraction for a given pair of media.
(ii) When a ray of light enters from one medium to another having different optical densities it bends. Why does this phenomenon occur ?
(iii) Write one condition where it does not bend when entering a medium of different optical density. [3]
(b) A lens produces a virtual image between the object and the lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the formation of this image. [3]
(c) What do you understand by the term ‘Scattering of light’ ? Which colour of white light is scattered the least and why ? [4]

Question 8:
(a) (i) Name the waves used for echo depth sounding.
(ii) Give one reason for their use for the above purpose.
(iii) Why are the waves mentioned by you not audible to us ? [3]
(b) (i) What is an echo ?
(ii) State two conditions for an echo to take place. [3]
(c) (i) Name the phenomenon involved in tuning a radio set to a particular station.
(ii) Define the phenomenon named by you in part (i) above.
(iii) What do you understand by loudness of sound ?
(iv) In which units is the loudness of sound measured ? [4]

Question 9:
(a) (i) Which particles are responsible for current in conductors ?
(ii) To which wire of a cable in a power circuit should the metal case of a geyser be connected ?
(iii) To which wire should the fuse be connected ? [3]
(b) (i) Name the transformer used in the power transmitting station of a power plant.
(ii) What type of current is transmitted from the power station ?
(iii) At what voltage is this current available to our household ? [3]
(c) A battery of emf 12V and internal resistance 2Ω is connected with two resistors A and B of resistance 4Ω and 6Ω respectively joined in series.

Find
(i) Current in the circuit.
(ii) The terminal voltage of the cell.
(iii) The potential difference across 6Ω Resistor.
(iv) Electrical energy spent per minute in 4Ω Resistor. [4]

Question 10:
(a) Arrange α, β and γ rays in ascending order with respect to their:
(i) Penetrating power.
(ii) Ionising power.
(iii) Biological effect.
(b) (i) In a cathode ray tube what is the function of anode ?
(ii) State the energy conversion taking place in a cathode ray tube.
(iii) Write one use of cathode ray tube. [3]
(c) (i) Represent the change in the nucleus of a radioactive element when α β particle is emitted.
(ii) What is the name given to elements with same mass number and different atomic number ?
(iii) Under which conditions does the nucleus of an atom tend to be radioactive ? [4]

 

ICSE Paper 2017
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

 

Section -1 [40 Marks]
(Attempt all questions from this Section)

Question 1.
(a) A brass ball is hanging from a stiff cotton thread. Draw a neat labelled diagram showing the forces acting on the brass ball and the cotton thread. [2]
(b) The distance between two bodies is doubled. How is the magnitude of gravitational force between them affected ? [2]
(c) Why is a jack screw provided with along arm? [2]
(d) If the power of a motor be 100 kW, at what speed can it raise a load of50,000 N? [2]
(e) Which class of lever will always have MA > 1 and why? [2]

Question 2.
(a) Define heat capacity and state its SI unit. [2]
(b) Why is the base of a cooking pan generally made thick ? [2]
(c) A solid of mass 50 g at 150°C is placed in 100 g of water at 11°C, when the final temperature recorded is 20°C. Find the specific heat capacity of the solidfSpecific heat capacity of water – 4.2 J g ^-1 °C ^-1 ). [2]
(d) How is the refractive index of a material related to :
(i) real and apparent depth ?
(ii) velocity of light in vacuum or air and the velocity of light in a given medium ?
(e) State the conditions required for total internal reflection of light to take place. [2]

Question 3.
(a) Draw a ray diagram to show the refraction of a monochromatic ray through a prism when it suffers minimum deviation. [2]
(b) The human ear can detect continuous sounds in the frequency range from 20 Hz to 20000 Hz. Assuming that the speed of sound in air is 330 ms^-1 for all frequencies, calculate the wavelengths corresponding to the given extreme frequencies of the audible range. [2]
(c) An enemy plane is at a distance of 300 km from a radar. In how much time the radar will be able to detect the plane? Take velocity of radio waves as 3 × 10⁸ m s^-1. [2]
(d) How is the frequency of a stretched string related to : [2]
(i) its length?
(ii) its tension?
(e) Define specific resistance and state its SI unit. [2]

Question 4.
(a) An electric bulb of resistance 500 Ω, draws a current of 0.4 A. Calculate the power of the bulb and the potential difference at its end. [2]
(b) State two causes of energy loss in a transformer. [2]
(c) State two characteristics of a good thermion emitter. [2]
(d) State two factors upon which the rate of emission of thermions depends. [2]
(e) When does the nucleus of an atom tend to be radioactive? [2]

Section – II [40 Marks]
(Attempt any four questions from this Section)

Question 5.
(a) A uniform half metre rule balances horizontally on a knife edge at 29 cm mark when a weight of 20 gf is suspended from one end.
(i) Draw a diagram of the arrangement
(ii) What is the weight of the half metre rule ? [3]
(b) A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
(ii) How does uniform circular motion differ from uniform linear motion ?
(iii) Name the process used for producing electricity using nuclear energy. [3]
(c) A pulley system with VR = 4 is used to lift a load of 175 kgf through a vertical height of 15 m. The effort required is 50 kgf in the downward direction, (g = 10 N kg^-1). [4]
Calculate:
(i) Distance moved by the effort.
(ii) Work done by the effort.
(iii) M.A. of the pulley system.
(iv) Efficiency of the pulley system.

Question 6.
(a) (i) How is the transference of heat energy by radiation prevented in a calorimeter ? [3]
(ii) You have a choice of three metals A, B and C, of specific heat capacities 900 J kg^-1 °C^-1, 380 / kg^-1 °C^-1 and 460 J kg^-1 °C^-1 respectively, to make a calorimeter. Which material will you select ? Justify your answer.
(b) Calculate the mass of ice needed to cool 150 g of water contained in a calorimeter of mass 50 g at 32°C such that the final temperature is 5°C.
Specific heat capacity of calorimeter 0.4 J g^-1 °C^-1
Specific heat capacity of water = 4.2 J g^-1 °C^-1
Latent heat capacity of ice 330 J g^-1 [3]
(c) (i) Name the radiations which are absorbed by greenhouse gases in the earth’s atmosphere.
(ii) A radiation X is focused by a particular device on the bulb of a thermometer and mercury in the thermometer shows a rapid increase. Name the radiation X.
(iii) Name two factors on which the heat energy liberated by a body depends. [4]

Question 7.
(a) A lens forms an upright and diminished image of an object when the object is placed at the focal point of the given lens.
(i) Name the lens.
(ii) Draw a ray diagram to show the image formation.
(b) A ray of light travels from water to air as shown in the diagram given below :
(i) Copy the diagram and complete the path of the ray. Given the critical angle for water is 48°.
(ii) State the condition so that total internal reflection occurs in the above diagram.

(c) The diagram below shows a point source P inside a water container. Four rays A, B, C, D starting from the source P are shown upto the water surface.

(i) Show in the diagram the path of these rays after striking the water surface. The critical angle for water air surface is 48°.
(ii) Name the phenomenon which the rays B and D exhibit:

Question 8.
(a) Name the factor that determines :
(i) Loudness of the sound heard.
(ii) Quality of the note.
(iii) Pitch of the note. [3]
(b) (i) What are damped vibrations ?
(ii) Give one example of damped vibrations.
(iii) Name the phenomenon that causes a loud sound when the stem of a vibrating tuning fork is kept pressed on the surface of a table. [3]
(c) (i) A wire of length 80 cm has a frequency of 256 Hz. Calculate the length of a similar wire under similar tension, which will have frequency 1024 Hz.
(ii) A certain sound has a frequency of 256 hertz and a wavelength of 1.3 m.
(1) Calculate the speed with which this sound travels.
(2) What difference would be felt by a listener between the above sound and another sound travelling at the same speed, but of wavelength 2.6 m ? [4]

Question 9.
(a) (i) Name the colour code of the wire which is connected to the metallic body of an appliance.
(ii) Draw the diagram of a dual control switch when the appliance is switched ‘ON’. [3]
(b) (i) Which particles are responsible for current in conductors ?
(ii) To which wire of a cable in a power circuit should the metal case of a geyser be connected ?
(iii) To which wire should the fuse be connected ? [3]
(c) (i) Explain the meaning of the statement ‘current rating of a fuse is 5A’.
(ii) In the transmission of power the voltage of power generated at the generating stations is stepped up from 11 kV to 132 kV before it is transmitted. Why ? [4]

Question 10.
(a) Answer the following questions based on a hot cathode ray tube :
(i) Name the charged particles.
(ii) State the approximate voltage used to heat the filament.
(iii) What will happen to the beam when it passes through the electric field ? [3]
(b) State three factors on which the rate of emission of electrons from a metal surface depends. [3]
(c) (z) What are free electrons ?
(ii) Why do they not leave the metal surface on their own ?
(iii) How can they be made to leave the metal surface ? (State any two ways) [4]

 

ICSE Paper 2018
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

Section – I [40 Marks]
(Attempt all questions from this Section)

Question 1.
(a) (i) State and define the SI unit of power. [2]
(ii) How is the unit horse power related to the SI unit of power?
(b) State the energy changes in the following cases while in use: [2]
(i) An electric iron.
(ii) A ceiling fan.
(c) The diagram below shows a lever in use: [2]
(i) To which class of levers does it belong?
(ii) Without changing the dimensions of the lever, if the load is shifted towards the fulcrum what happens to the mechanical advantage of the lever?

(d) (i) Why is the ratio of the velocities of light of wavelengths 4000 A and 8000 A in vacuum 1:1?
(ii) Which of the above wavelengths has a higher frequency? [2]
(e) (i) Why is the motion of a body moving with a constant speed around a circular path said to be accelerated?
(ii) Name the unit of physical quantity obtained by the formula 2K/V² where K: kinetic energy, V: Linear velocity.[2]

Question 2.
The power of a lens is -5D. [2]
(a) (i) Find its focal length.
(ii) Name the type of lens.
(b) State the position of the object in front of a converging lens if:[2]
(i) It produces a real and same size image of the object.
(ii) It is used as a magnifying lens.
(c) (i) State the relation between the critical angle and the absolute refractive index of a medium.
(ii) Which colour of light has a higher critical angle? Red light or Green light. [2]
(d) (i) Define scattering. [2]
(ii) The smoke from a fire looks white. Which of the following statements is true?
1. Molecules of the smoke are bigger than the wavelength of light.
2. Molecules of the smoke are smaller than the wavelength of light.
(e) The following diagram shows a 60°, 30°, 90° glass prism of critical angle 42°. Copy the diagram and complete the path of incident ray AB emerging out of the prism marking the angle of incidence on each surface.[2]

Question 3.
(a) Displacement distance graph of the two sound waves A and B, travelling in a medium, are as shown in the diagram below.

Study the two sound waves and compare their:
(i) Amplitudes
(ii) Wavelengths
(b) You have three resistors of values 2 Ω , 3 Ω and 5 Ω How will you join them so that the total resistance is more than 7 Ω? [2]
(i) Draw a diagram for the arrangement.
(ii) Calculate the equivalent resistance.
(c) (i) What do you understand by the term nuclear fusion? [2]
(ii) Nuclear power plants use nuclear fission reaction to produce electricity. What is the advantage ofproducing electricity by fusion reaction?
(d) (i) What do you understand by free vibrations of a body? [2]
(ii) Why does the amplitude of a vibrating body continuously decrease during damped vibrations?
(e) (i) How is the emf across primary and secondary coils of a transformer related with the number of turns of coil in them? [2]
(ii) On which type of current do transformers work?

Question 4.
(a) (i) How can a temperature in degree Celsius be converted into SI unit of temperature? [2]
(ii) A liquid X has the maximum specific heat capacity and is used as a coolant in Car radiators. Name the liquid X.
(b) A solid metal weighing 150 g melts at its melting point of800 °C by providing heat at the rate of 100 W The time taken for it to completely melt at the same temperature is 4 mm. What is the specific latent heat of fusion of the metal? [2]
(c) Identify the following wires used in a household circuit: [2]
(i) The wire is also called as the phase wire.
(ii) The wire is connected to the top terminal of a three-pin socket.
(d) (i) What are isobars? [2]
(ii) Give one example of isobars.
(e) State any two advantages of electromagnets over permanent magnets. [2]

Section – II [40 Marks]
(Attempt any FOUR Questions from this Section)

Question 5.
(a) (i) Derive a relationship between SI and C.G.S. unit of work. [3]
(ii) A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of force. What should be the value of θ to get the maximum positive work?
(b) A half metre rod is pivoted at the centre with two weights of 20 gf and 12 gf suspended at a perpendicular distance of 6 cm and 10 cm from the pivot respectively as shown below [3]

(i) Which of the two forces acting on the rigid rod causes clockwise moment?
(ii) Is the rod in equilibrium?
(iii) The direction of 20 kgf force is reversed. What is the magnitude of the resultant moment of the forces on the rod?
(c) (i) Draw a diagram to show a block and tackle pulley system having a velocity ratio of 3 marking the direction of load(L), effort(E) and tension(T).
(ii) The pulley system drawn lifts a load of 150 N when an effort of 60 N is applied. Find its mechanical advantage.
(iii) Is the above pulley system an ideal machine or not? [4]

Question 6.
(a) A ray of light XY passes through a right angled isosceles prism as shown below [3]

(i) What is the angle through which the incident ray deviates and emerges out of the prism?
(ii) Name the instrument where this action of prism is put into use.
(iii) Which prism surface will behave as a mirror?
(b) An object AB is placed between O and F₁ on the principal axis of converging lens as shown in the diagram.

Copy the diagram and by using three standard rays starting from point A, obtain an image of the object AB.
(c) An object is placed at a distance of 12 cm from a convex lens of focal length. 8 cm. Find: [4]
(i) the position of the image
(ii) nature of the image

Question 7.
(a) Draw the diagram of a right angled isosceles prism which is used erect. [3]
(b)
[3]
The diagram above shows a wire stretched over a sonometer. Stems of two vibrating tuning forks A and B are touched to the wooden box of the sonometer. It is observed that the paper rider (a small piece of paper folded at the centre) present on the wire flies off when the stem of vibrating tuning fork B is touched to the wooden box but the paper just vibrates when the stem of vibrating tuning fork A is touched to the wooden box.
(i) Name the phenomenon when the paper rider just vibrates.
(ii) Name the phenomenon when the paper rider flies off.
(iii) Why does the paper rider fly off when the stem of tuning fork B is touched to the box?
(c) A person is standing at the sea shore. An observer on the ship, which is anchored in between a vertical cliff and the person on the shore, fires a gun. The person on the shore hears two sounds, 2 seconds and 3 seconds after seeing the smoke of the fired gun. If the speed of sound in the air is 320 m s^-1 then calculate:
(i) the distance between the observer on the ship and the person on the shore.
(ii) the distance between the cliff and the observer on the ship. [4]

Question 8.
(a) (i) A fuse is rated 8 A. Can it be used with an electrical appliance rated 5 kW, 200 V? Give a reason. [3]
(ii) Name two safety devices which are connected to the live wire of a household electric circuit.
(b) (i) Find the equivalent resistance between A and B. [3]

(ii) State whether the resistivity of a wire changes with the change in the thickness of the wire.
(c) An electric iron is rated 220 V, 2 kW. [4]
(i) If the iron is used for 2 h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
(ii) Why is the fuse absolutely necessary in a power circuit?

Question 9.
(i) Heat supplied to a solid change it into liquid. What is this change in phase called ? [3]
(ii) During the phase change does the average kinetic energy of the molecules of the substance increase?
(iii) What is the energy absorbed during the phase change called?
(b) (i) State two differences between “Heat Capacity” and “Specific Heat Capacity”. [3]
(ii) Give a mathematical relation between Heat Capacity and Specific Heat Capacity.
(c) The temperature of 170 g of water at 50°C is lowered to 5°C by adding certain amount of ice to it. Find the mass of ice added. Given: Specific heat capacity of water = 4200 J kg^-1 °C^-1 and Specific latent heat of ice 336000 J kg^-1. [4]

Question 10.
(a) The diagram shows a coil wound around a U shape soft iron bar AB.
(i) What is the polarity induced at the ends A and B when the switch is pressed?
(ii) Suggest one way to strengthen the magnetic field in the electromagnet.
(iii) What will be the polarities at A & B if the direction of current is reversed in the circuit? [3]

(b) The ore of Uranium found in nature contains ₉₂U²³⁸ and ₉₂U²³⁵. Although both the isotopes are fissionable, it is found out’experimentally that one of the two isotopes is more easily fissionable.
(i) Name the isotope of Uranium which is easily fissionable.
(ii) Give a reason for your, answer.
(iii) Write a nuclear reaction when Uranium 238 emits an alpha particle to form a Thorium (Th) nucleus. [3]
(c) Radiations given out from a, source when subjected to an electric field in a direction perpendicular to their path are shown below in the diagram. The arrows show the path of the radiation A, B and C. Answer the following questions in terms of A, B and C. [4]
(i) Name the radiation B which is unaffected by the electrostatic field.
(ii) Why does the radiation C deflect more than A?

(iii) Which among the three causes the least biological damage externally?
(iv) Name the radiation which is used in carbon dating.

ICSE Paper 2019
PHYSICS

(Two hours)
Answers to this Paper must he written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to he spent in reading the question paper.
The time given at the head of this Paper is the time allowed for writing the answers.
Section I is compulsory. Attempt any four questions from Section II.
The intended marks for questions or parts of questions are given in brackets [ ].

Section – I[40 Marks]
(Attempt all questions from this Section)

Question 1.
(a) The diagram below shows a claw hammer used to remove a nail:

(i) To which class of lever does it belong ?
(ii) Give one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one.
(b) Two bodies A and B have masses in the ratio 5:1 and their kinetic energies are in the ratio 125:9. Find the ratio of their velocities. [2]
(c) (i) Name the physical quantity which is measured in calories
(ii) How is calorie related to the SI unit of that quantity? [2]
(d) (i) Define couple.
(ii) State the SI unit of moment of couple. [2]
(e) (i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium. [2]

Question 2.
(a) An electromagnetic radiation is used for photography in fog.
(i) Identify the radiation.
(ii) Why is this radiation mentioned by you, ideal for this purpose? [2]
(b) (b) (i) What is the relation between the refractive index of water with respect to air (_aμ_w) and the refractive index of air with respect to water (_wμ_a)
(ii) If the refractive index of water ivith respect to air (_aμ_w) is 53. Calculate the refractive index of air ivith respect to water (_wμ_a) [2]
(c) The specific heat capacity of a substance A is 3,800 J kg^-1K^-1 and that of a substance B is 400 J Kg^-1K^-1. Which of the two substances is a good conductor of heat? Give a reason for your answer. [2]
(d) A man playing a flute is able to produce notes of different frequencies. If he closes the holes near his mouth, will the pitch of the note produced, increase or decrease? Give a reason. [2]
(e) The diagram below shows a light source P embedded in a rectangular glass block ABCD of
critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles.] [2]

Question 3.
(a) (i) If the lens is placed in water instead of air, how does its focal length change?
(ii) Which lens, thick or thin has greater focal length? [2]
(b) Two waves of the same pitch have amplitudes in the ratio 1 : 3.
What will be the ratio of their:
(i) intensities and
(ii) frequencies? [2]
(c) How does an increase in the temperature affect the specific resistance of a :
(i) Metal and
(ii) Semiconductor? [2]
(d) (i) Define resonant vibrations.
(ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him ? [2]
(e) Is it possible for a hydrogen (₁¹H) nucleus to emit an alpha particle? Give a reason for your
answer. [2]

Question 4.
(a) Calculate the effective resistance across AB :

(b) (i) State whether the specific heat capacity of a substance remains the same when its state changes from solid to liquid.
(ii) Give one example to support your answer. [2]
(c) A magnet kept at the centre of two coils A and B is moved to and fro as shouni in the diagram. The two galvanometers show deflection.

State with a reason whether :
x > y or x <y [x and y are magnitudes of deflection] [2]
(d) (i) Why is a nuclear fusion reaction called a thermo nuclear reaction?
(ii) Complete the reaction : [2]
³ He₂ + ²H₁→ ⁴He₂ +…….+Energy
(e) State two ways to increase the speed of rotation of a DC motor. [2]

Section – II [40 Marks]
(Attempt any four questions from this Section)

Question 5.
(a) A body of mass 10 kg is kept at a height of 5 m. It is allowed to fall and reach the ground.
(i) What is the total mechanical energy possessed by the body at the height of 2 m assuming it is a frictionless medium?
(ii) What is the kinetic energy possessed by the body just before hitting the ground? Take
g= 10 m s^-2. [3]
(b) A uniform metre scale is in equilibrium as shown in the diagram :

(i) Calculate the weight of the metre scale.
(ii) Which of the following options is correct to keep the ruler in equilibrium when 40 gf wt is shifted to 0 cm mark?
F is shifted towards 0 cm or
F is shifted towards 100 cm. [3]
(c) The diagram below shows a pulley arrangement :

(i) Copy the diagram and mark the direction of tension on each strand of the string.
(ii) What is the velocity ratio of the arrangement?
(iii) If the tension acting on the string is T, then what is the relationship between T and effort E?
(iv) If the free end of the string moves through a distance x, find the distance by which the
load is raised.

Question 6.
(a) How does the angle of deviation formed by a prism change with the increase in the angle of
incidence? Draw a graph showing the variation in the angle of deviation with the angle of incidence at a prism surface. [3]
(b) A virtual, diminished image is formed when an object is placed between the optical centre and the principal focus of a lens.
(i) Name the type of lens which forms the above image.
(ii) Draw a ray diagram to show the formation of the image with the above stated characteristics. [3]
(c) An object is placed at a distance 24 cm in front of a convex lens of focal length 8 cm.
(i) What is the nature of the image so formed ?
(ii) Calculate the distance of the image from the lens.
(iii) Calculate the magnification of the image. [4]

Question 7.
(a) It is observed that during march-past we hear a base drum distinctly from a distance compared to the side drums.
(i) Name the characteristic of sound associated with the above observation.
(ii) Give a reason for the above observation. [3]
(b) A pendulum has a frequency of 4 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after 6 vibrations of the pendulum. If the velocity of sound in air is 340 m s1, find the distance between the cliff and the observer. [3]
(c) Two pendulums C and D are suspended from a wire as shown in the given figure. Pendulum C is made to oscillate by displacing it from its mean position. It is seen that D also starts oscillating.

(i) Name the type of oscillation, C will execute.
(ii) Name the type of oscillation, D will execute.
(iii) If the length of D is made equal to C, then what difference will you notice in the oscillations ofD?
(iv) WHat is the name of the phenomenon when the length of D is made equal to C? [4]

Question 8.
(a) (i) Write one advantage of connecting electrical appliances in parallel combination.
(ii) What characteristics should a fuse wire have?
(iii) Which wire in a power circuit is connected to the metallic body of the appliance? [3]
(b) The diagram below shows a dual control switch circuit connected to a bulb.

(i) Copy the diagram and complete it so that the bulb is switched ON.
(ii) Out of A & B which one is the live wire and which one is the neutral wire?
(c) The diagram shows a circuit with the key k open.

Calculate:
(i) the resistance of the circuit when the key k is crpen.
(ii) the current drawn from the cell when the key k is open,
(iii) the resistance of the circuit when the key k is closed.
(iv) the current drawn from thexell when the key k is closed.

Question 9.
(a) (i) Define Calorimetry.
(ii) Name the material used for making a Calorimeter.
(iii) Why is a Calorimeter made-up of thin sheets of the above material answered in (ii) ? [3]
(b) The melting point of naphthalene is 80°C and the room temperature is 30°C. A sample of
liquid naphthalene at 100°C is cooled down to the room temperature. Draw a temperature¬time graph to represent this cooling. In the graph, mark the region which corresponds to the freezing process. [3]
(c) 104 g of water at 30°C is taken in a calorimeter made of copper of mass 42 g. When a certain mass of ice at 0°C is added to it, the final steady temperature of the mixture after the ice has melted, was found to be 10°C. Find the mass of ice added.
[Specific heat capacity of water = 4.2 J g^-1 °C^-1  : Specific latent heat of fusion of ice – 336 J g^-1 ; Specific heat capacity of copper = 0.4 J g^-1 °C^-1 ] [4]

Question 10.
(a) Draw a neat labelled diagram of an AC generator.
(b) (i) Define nuclear fission.
(ii) Rewrite and complete the following nuclear reaction by filling in the atomic number of Ba and mass number of Kr : [3]

(c) The diagram below shows a magnetic needle kept just below the conductor AB which is kept in North South direction.

(i) In which direction does the needle deflect when the key is closed ?
(ii) Why is the deflection produced?
(iii) What will he the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle. [4]