Students should refer to ICSE Class 10 Physics Question Paper solved Set J given below which will help them to prepare for the upcoming ICSE Physics exams. Students should read ICSE Physics Class 10 Books to make sure they are completely prepared and should also refer to ICSE Class 10 Physics Solutions to understand all questions and their answers.
ICSE Class 10 Physics Question Paper solved Set J
Answers to this paper must be written on the paper provided separately.
You will not be allowed to write during the first 15 minutes.
This time is to be 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 [ ].
ICSE Class 10 Physics Question Paper solved Set J
SECTION – I (40 Marks)
(Attempt all Questions)
Question 1.
(a) Name the device used for measuring :
(i) mass (ii) weight (2)
(b) A boy weights 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 2m s–1.
What potential energy did the spring possess when compressed ? (2)
(e) Name the subjective property
(i) of sound related to its frequency.
(ii) of light related to its wavelength. (2)
Answer
(a) (i) Physical balance (ii) Spring balance
(b) Weight of the boy on the earth = 360 N
(i) Approximate weight on the moon = 1/6 × 360 = 60 N
(ii) The weight on the moon has been reduced because acceleration due to gravity on the moon is 1/6th that on the surface of the earth. (_ W = mg), therefore the weight is reduced to 1/6 i.e., 60 N
(c) We know that W = FS cosq. clearly, work done by the force will be zero if.
(i) S = 0 i.e., no displacement takes place
(ii) If q = 90º, then cos 90º = 0, and W = 0 i.e., when the force acts perpendicular to the direction of motion.
(d) When spring is compressed, there is a potential energy stored in it. When the trolley is released the potential energy of spring is converted into kinetic energy of the trolley.
∴ P.E. of the spring = 1/2mv2 = 1/2 × 0.5 × 2 × 2 = 1J
(e) (i) Pitch (ii) Colour
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 ?
( c ) ‘The refractive index of diamond is 2.42;. What is meant by this statement ? (2)
(d) We can burn a piece of paper by focussing the sun rays by using a particular type of lens.
(i) Name the type of lens used for the above purpose.
(ii) Draw a ray diagram to support your answer. (2)
(e) A ray of light enters a glass slab PQRS, as shown in the diagram. The critical angle of the glass is 42º. Copy this diagram and complete the path of the ray till it emerges from the glass slab.
Mark the angle in the diagram wherever necessary.
Answer.
(a) (i) The mechanical advantage of second order levers is always more than 1 because the effort arm is always longer than the load arm.
(ii) A single movable pulley.
(b) (i) Bending of light as it travels from one medium into another is called the refraction of light.
(ii) The refraction of light takes place because the velocity of light in different media is different.
( c ) It means that the ratio of the velocity of light in vacuum to the velocity of light in diamond is 2.42.
(d) (i) A convex lens is used to focus the sun rays on a piece of paper to burn it. A large amount of heat gets concentrated at a point and is sufficient to burn the piece of paper.
(ii) The necessary ray diagram is given below.
(e) The copied diagram alongwith the complete path of the ray is as shown below :
The angle of incidence on PQ is 48º which is greater than the critical angle. Hence, total internal r eflection takes place at PQ. OT is the totally reflected ray. It is incident on PS at 42º and will be refracted along TS.
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.
(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)
Answer.
(a) The two main difference are :
(b) (i) Since loudness is proportional to the square of the amplitude, therefore loundess will be in ratio of (2)2 : (3)2 i.e., 4 : 9.
(ii) Since their pitch is the same, therefore their frequencies will be same i.e., their ratio is 1 : 1.
(d) Clearly, the resistance of 2Ω, 3Ω and 5Ω are in series.
∴ Total resistance is 2W + 3Ω + 5Ω = 10Ω and the circuit reduces to as shown.
Now, 10Ω and 10Ω are in parallel, there combined resistance R’ is :
Now, 2Ω, 5Ω, 5Ω are in series, therefore the net resistance is :
R = 2Ω + 5Ω + 5Ω = 12Ω
(e) (i) The metallic part of an electrical appliance is earthed.
(ii) The required relation is P =V2/R, where P is power, V the potential difference and R is the resistance.
Question 4.
(a) A device is used to transform 12V a.c. to 200V a.c.
(i) What is the name of this device ?
(ii) Name the principle on which it works. (2)
(b) (i) Which material 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 :
(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)
Answer.
(a) (i) Since the device is being used to step up 12 V a.c. to 200 V a.c., it is called a step up transformer.
(ii) A transformer works on the principle of mutual induction.
(b) (i) The calorimeter is usually made of copper.
(ii) Copper is a good conductor of heat. It therefore, takes less time to acquire the same temperature as that of the liquid in it.
(c) (i) Tungsten or thoriated tungsten.
(ii) High melting point and low work function.
(d) (i) The completed nuclear changes are as below (use the fact that total mass number and charge numbers are always conserved in a nuclear change.
(e) (i) g rays.
(ii) There is no change in the atomic number as g rays are uncharged.
ICSE Class 10 Physics Question Paper solved Set J
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.
(b) A body of mass 50 kg has a momentum of 3000 kg m s–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%.
Answer.
(a) (i) Momentum of a body is defined as the quantity of motion contained in the body. It is measured by the product of mass and velocity of the body.
(ii) Force is equal to the rate of change of momentum of the body i.e.,
(iii) The necessary condition is that mass of the body is constant and does not change
with velocity.
(ii) M.A. of an inclined plane =1 / sin θ , where q is the angle of the inclined plane.
(iii) The efficiency of a single movable pulley is less than 100% because—Friction is always present. A part of the energy is always used up in overcoming friction.
The pulley is not weightless.
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.
Answer.
(a)
The stick appears to be bent upwards and seems to be shortened. This is due to refraction of light.
(c) If virtual, erect and magnified image of an object placed between the optical centre and principal focus of a lens is formed, then lens must be convex.
(i) Convex lens
(ii) The diagram is as shown below :
Question 7.
(a) Two parallel rays Red and Violet travelling through air, meet the air-glass boundary as shown in the above figure :
(i) Will their paths inside the glass be parallel ? Give a reason for your answer.
(ii) Compare the speeds of the two rays inside the glass.
(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 m s–1.
(ii) If the man had been standing at a distance of 12 m from the cliff would he have hear the 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. Unit.
(ii) Why should switches always be connected to the live wire ?
(iii) Give one precaution that should be taken while handling switches.
Answer.
(a) The paths of two parallel red and violet colour rays travelling through air are as shown :
(i) Since the refractive index of glass for violet colour is more. It will bend more than
the red colour as shown : The paths inside the glass will not be parallel.
(ii) Velocity of red colours will be more than that of the violet colour.
(b) (i) The time t after which an echo is heard is given by,
(ii) Man can not heard a clear echo because if man had been standing at a distance 12 m
which is less than 0.1 s.
(c) (i) The domestic electric meter measure, the electric energy in kWh. 1 kWh = 3.6 × 106J
(ii) The switch should always be connected to the live wire, so that current is cut off to that appliance to which it is connected.
(iii) The switches should not be touched with wet hand otherwise we may receive a shock.
Question 8.
(a) Calculate the quantity of heat that will be produced in a coil of resistance 75Ω if a current of 2 A is passed through it for 2 minutes. (3)
(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.
Answer.
(a) Here, R = 75Ω, i = 2A, t = 2 minutes = 2 × 60 = 120s
Now, Heat produced
H = i2Rt
= 2 × 2 × 75 × 120J = 36000 J = 8571.4 calories.
(b) (i) Superconductor
(ii) The resistance of a metallic wire is affected by
1. Its area of cross-section.
2. Its temperature.
(c) To solve the above Question, we have to first find the total resistance of the circuit.
(i) Here we find that R1 and R2 are in parallel and their combined resistance R¢ is given
by R’ = 10 x 40 / 10 + 40 = 8Ω
Also, the resistances of 30Ω, 20Ω and 60Ω are in parallel and their combined resistance
R” is given by 1/R” = 1/30 + 1/20 + 1/60
= 2 + 3 + 1 / 60 = 6/60
∴ R” = 60/6 = 10Ω
Now, R’ and R” are in series and their combined resistance R is given by
R = R’ + R” = 8Ω + 10Ω = 18Ω
∴ Total resistance in the circuit = 18Ω
(ii) Now, I = v/R = 12V/18Ω = 2/3 A = 0.67 A
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 0ºC is added to 300g of a liquid at 30ºC. What will be the final temperature of the mixture when all the ice has melted ? The specific heat capacity of the liquid as 2.65 J g–1 ºC–1 while that of water is 4.2 J g–1ºC–1. Specific latent heat of fusion of ice = 336 J g–1. (4)
Answer.
(a) (i) Specific latent heat of fusion : It is defined as the heat required to melt one kilogram of a substance at its melting point without any change in temperature.
(ii) Water has the highest specific heat capacity.
(iii) The heat absorbed or given out by a substance depends upon (i) mass of the body, (ii) rise or fall of temperature.
(b) (i) Heat absorbed by a substance is given by
H = msø
H = Heat capacity × rise of temperature.
Since, H is same for both A and B, it is a clear that heat capacity is inversely proportional to the rise of temperature.
Since, the rise of temperature A is more its heat capacity must be less.
∴ Heat capacity of A is less than that of B.
1. The energy of the molecules of a body increases with the rise in temperature and decreases with the fall of temperature.
2. Since, temperature remains constant there is no change in the kinetic energy of the molecules. The energy given to substance to change the state of the substances increases potential energy of the molecules.
(c) Here
Let ø be the final temperature of the mixture.
Heat gained by 50g of ice at 0ºC during its change of state to water =mL = 50 × 336 = 16800 J
Heat gained by 50g of water when its temperature rises to øºC = 50 × 4.2 × ø = 210ø
Total heat gained = 16800 + 210øJ
Heat lost by the liquid = 300 × 2.65 × (30 – ø)
= 300 × 2.65 × 30 – 300 × 2.65ø = 23850 – 795ø
Now, Heat gained = Heat lost
16800 + 210ø = 23850 – 795ø
or 1005ø = 23850 – 16800 = 7050
∴ ø = 7050/1005 = 7ºC
Question 10.
(a) (i) Name the radioactive radiations which have the least penetrating power.
(ii) Give one use of radioisotopes.
(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 a electric bell ? Give a reason for using this material. (4)
Answer.
(a) (i) a-rays have the least penetrating power.
(ii) Radioisotopes are used to study the function of fertilizer for different plants. They have also been used for developing new species of a plant by causing genetic changes.
(iii) Background radiations are present at all places even in the absence of any radioactive source. The radiations are present in the atmosphere even when there is no source nearby. The source of background radiations are :
(a) cosmic radiation (b) rocks in the earth which contain traces of radioactive substances (c) naturally occurring radioisotopes.
(b) (i) The direction of the magnetic lines of force will be anticlockwise. The iron filings will align themselves in circular lines of force (By Right hand thumb rule.)
(ii) Right hand thumb rule or Maxwell’s cork screw rule.
(c) (i) The magnetic field along the axis of a solenoid is given by B = μoni
Clearly, the magnetic field can be increased by
1. Increasing the current.
2. Increasing the number of turns/length.
(ii) The armature of the electric bell is made of iron. This is because iron when magnetised is quickly demagnetised when the circuit is broken. Steel armature might lock up the circuit and the bell may not work.