Solving ICSE Class 10 Physics Previous Year Question Papers ICSE Class 10 Physics Question Paper 2019 is the best way to boost your preparation for the board exams.
ICSE Class 10 Physics Question Paper 2019 Solved
Time: 1½ hours
Maximum Marks: 80
General Instructions:
- Answers to this paper must be written on ihe 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 [ ].
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; [2]
(i) To which class of lever does it belong?
(ii) Given one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one.
Answer:
(i) Class One.
(ii) Shears used for cutting the thin metal sheets.
(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]
Answer:
Given \(\frac{m_{\mathrm{A}}}{m_{\mathrm{B}}}\) = \(\frac{5}{1}\)
Kinetic energy is given by K = \(\frac{1}{2} m v^2\)
(c) (i) Name the physical quantity which is measured in calories. [2]
(ii) How is calories related to the S.I. unit of that quantity?
Answer:
(i) Heat energy.
(ii) 1 cal = 4.2 J.
(d) (i) Define couple. [2]
(ii) State the S.I. unit of moment of couple.
Answer:
(i) It is defined as a set of two equal and opposite forces acting along different lines of action.
(ii) SI unit is N m.
(e) (i) Define critical angle. [2]
(ii) State one important factor which affects the critical angle of a given medium.
Answer:
(i) It is the angle of incidence in the denser medium for which angle of refraction in the rarer medium is 90°.
(ii) Nature of the two media in contact.
Question 2.
(a) An electromagnetic radiation is used for photography in fog. [2]
(i) Identify the radiation.
(ii) Why is this radiation mentioned by you, ideal for this purpose?
Answer:
(i) infrared radiation.
(ii) Because it can penetrate fog.
(b) (i) What is the relation between the refractive index of water with respect to air (aµw) and the refractive index of air with respect to water (wµa). [2]
(ii) If the refractive index of water with respect to air (aµw) is \(\frac{5}{3}\)
Calculate the refractive index of air with respect to water (wµa).
Answer:
(i) The relation is aμw = \(\frac{1}{{ }_w \mu_a}\)
(ii) Given wμa = \(\frac{5}{3}\), therefore,
we have wμa = \(\frac{1}{a \mu_w}\) = \(\frac{1}{5 / 3}\) = \(\frac{3}{5}\)
(c) The specific heat capacity of a substance A is 3,800 Jkg-1K-1 and that of a substance B is 400 Jkg-1K-1. Which of the two substances is a good conductor of heat? Give a reason for your answer. [2]
Answer:
Substance B. Because it requires relatively little heat to raise its temperature.
(d) A man playing a flute is able to produce notes of different frequencies. If he closes the holders near his mouth, will the pitch of the note produced, increase or decrease? Given a reason. [2]
Answer:
The pitch will decrease, as the pitch is inversely proportional to the length of the vibrating air column.
(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]
Answer:
The path of ray is as shown:
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?
Answer:
(i) Its focal length increases.
(ii) Thin lens.
(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?
Answer:
(i) Ratio of intensities will be 1: 9.
(ii) Ratio of frequencies will be 1 : 1.
(c) How does an increase in the temperature affect the specific resistance of a : [2]
(i) Metal and
(ii) Semiconductor?
Answer:
(i) Increases.
(ii) Decreases.
(d) (i) Define resonant vibrations. [2]
(ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him?
Answer:
(i) If a body is made to vibrate with its fundamental frequency by an external source, then the vibrations are called resonant vibrations.
(ii) Quality.
(e) It is possible for a hydrogen (H) nucleus to emit an alpha particle? [2]
Answer:
No, as it does not possess a helium nucleus.
Question 4.
(a) Calculate the effective resistance across AB : [2]
Answer:
Resistors of 5Ω and 4Ω are in senes, therefore, their net resistance is RS = 5 + 4 = 9Ω.
Now, this 9Ω and 3Ω are in parallel, hence net resistance
RP = \(\frac{9 \times 3}{9+3}\) = \(\frac{18}{12}\) = 1.5Ω
Now, this is in series with the 8Ω resistor, hence net resistance of the circuit is
RT = 8 + 1.5 = 9.5Ω
(b) (i) State whether the specific heat capacity of a substance remains the same when its state changes from solid to liquid.
(ii) Given one example to support your answer. [2]
Answer:
(i) No, specific heat capacity does not remain the same when it changes from solid to liquid.
(ii) Let us take the example of water.
Specific heat capacity of water
= 4.2 J kg-1K-1
and specific heat capacity of ice
= 2.1 J kg-1K-1
(c) A magnet kept at the centre of two coils A and B is moved to and fro as shown in the diagram. The two galvanometers show deflection. [2]
Answer:
x
(d) State with a reason whether:
x > y or x < y [x and y are magnitudes of deflection.]
(i) Why a nuclear fusion reaction is called a thermos nuclear reaction?
(ii) Complete the reaction:
3He2 + 2H1 → 4He2 + ………… + Energy
Answer:
(i) Because this occurs at a very high temperature.
(ii) 3He2 + 2H2 → 4He1 + 1H1 + Energy
(e) State two ways to increase the speed of rotation of a D.C. motor.
Answer:
The two ways are
(i) Strong magnet and
(ii) High current.
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. [3]
(i) What is the total mechanical energy possessed by the body at the height of 2m assuming it is a friction less medium?
(ii) What is the kinetic energy possessed by the body just before hitting the ground?
Take g = 10m/s2.
Answer:
(i) The total mechanical energy is the total potential energy it possesses before its fall.
E = mgh = 10 × 10 × 5 = 500 J
(ii) It is equal to the maximum potential energy E = mgh
= 10 × 10 × 5 = 500J.
(b) A uniform meter scale is in equilibrium as shown in the diagram: [3]
(i) Calculate the weight of the meter 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.
Answer:
(i) The weight of the metre scale acts at its centre of gravity i.e., at 50 cm mark.
By the concept of moments, we have
40 × (30 – 5) = W × (50 – 30)
or W = (40 × 25)/20 = 50 gf
(ii) F is shifted towards 0 cm.
(c) The diagram below shown a pulley arrangement: [4]
(i) Copy the diagram and mark the direction of tension on each stand 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.
Answer:
(i) The direction of tension is as marked.
(ii) VR = Distance travelled by effort/Distance travelled by load = \(\frac{x}{2}\).
The distance travelled by load is half the distance moved by effort = \(\frac{x}{2}\)
(iii) T= E,
(iv) The distance travelled by load is half the distance moved by effort = \(\frac{x}{2}\).
Question 6.
(a) How does the angle of deviation formed by a prism change with the increase in the angle of incidence? [3]
Draw a graph showing the variation in the angle of deviation with the angle of incidence at a prism surface.
Answer:
As the angle of incidence increases the angle of deviation decreases becomes minimum and then increases. The graph is as shown:
(b) A virtual, diminished image is formed when an object is placed between the optical centre and the principal focus of a lens. [3]
(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.
Answer:
(i) Concave lens
(ii) The ray diagram is as shown:
(c) An object is placed at a distance of 24 cm from a convex lens of focal length 8 cm. [4]
(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.
Answer:
Given u = -24 cm, f = +8 cm, v = ?
(i) Real, inverted and diminished.
(ii) Using the lens formula
\(\frac{1}{f}\) = \(\frac{1}{v}\) – \(\frac{1}{u}\) ⇒ \(\frac{1}{v}\) = \(\frac{1}{f}\) + \(\frac{1}{u}\)
\(\frac{1}{v}\) = \(\frac{1}{8}\) + \(\frac{1}{(-24)}\) = \(\frac{3-1}{24}\) = \(\frac{2}{24}\) = \(\frac{1}{12}\)
v = +12 cm
(iii) Using the expression m = \(\frac{v}{u}\) = \(\frac{12}{-24}\) = \(\frac{1}{2}\)
Question 7.
(a) It is observed that during march-past we hear a base drum distinctly from a distance compared to the side drums. [3]
(i) Name the characteristic of sound associated with the above observation,
(ii) Given a reason for the above observation.
Answer:
(i) Intensity of sound.
(ii) This is because the amplitude of vibration of a base drum is far greater than the amplitude of vibration of the side drum.
(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/s, find the distance between the cliff and observer. [3]
Answer:
Given f = 4 vbs, T = \(\frac{1}{f}\) = \(\frac{1}{4}\) = 0.25 s, for a frequency of
6 vbs times t = \(\frac{0.25}{4}\) × 6 = 0.375 s, V = 340 ms-1,
Using S = \(\frac{\mathrm{V} \times t}{2}\) = \(\frac{340 \times 0.375}{2}\) = 63.75 m
(c) Two pendulums C and D are suspended from a wire as shown in the figure given below. 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 of D?
(iv) What is the name of the phenomenon when the length of D is made equal to C?
Answer:
(i) Free or natural oscillation.
(ii) Forced oscillation.
(iii) The amplitude of the oscillation of D will be equal to the amplitude of the oscillation of C.
(iv) Resonance.
Question 8.
(a) (i) Write one advantage of connecting electrical appliance in parallel combination. [3]
(ii) What characteristic should a fuse wire have?
(iii) Which wire in a power circuit is connected to the metallic body of the appliance?
Answer:
(i) All appliances will continue to work even if one of the appliance does not work.
(ii) High resistivity and low melting point.
(iii) The ground wire.
(b) The diagram below shows a dual control switch circuit connected to a bulb.
(i) Copy the diagram and complete it so that bulb is switch ON.
(ii) Out of A & B which one is the live wire and which one is the neutral wire?
Answer:
(i) The diagram is as shown:
(ii) A is connected to the live wire and B to neutral wire.
(c) The diagram below shows a circuit with the key k open. Calculate :
(i) the resistance of the circuit when the key k is open.
(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 the cell when the key k is closed.
Answer:
(i) RS = 5 + 0.5 = 5.5Ω
(ii) I = \(\frac{V}{R}\) = \(\frac{3.3}{5.5}\) = 0.6A
(iii) RP = \(\frac{5 \times 5}{5+5}\) = 2.5Ω, thus total resistance is
RT = 2.5 + 0.5 = 30Ω
(iv) I = \(\frac{\mathrm{V}}{\mathrm{R}_{\mathrm{T}}}\) = \(\frac{3.3}{3.0}\) = 1.1 A
Question 9.
(a) (i) Define Calorimetry. [3]
(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)?
Answer:
(i) Calorimetry is the measurement of heat.
(ii) Copper.
(iii) Copper has small specific heat capacity. The thin sheets ensure that the box has small heat capacity.
(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]
Answer:
The graph is as shown:
(c) 104 g of water at 30°C is taken in a calorimeter made of copper of mass 42g. When a certain mass of ice at 0°C is added to it, the final 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 Jg-loC-1; Specific latent heat of fusion of ice = 336 Jg-1; Specific heat capacity of copper = 0.4 Jg-loC1] [4]
Answer:
Mass of water m1 = 104g
Temperature of water T1 = 30°C
Final temperature T2 = 10°C
Mass of calorimeter m2 = 42 g
Temperature of ice T3 = 0°C
Let the mass of ice added be = x g
Total heat energy lost
= (104 × 4.2 × 20) + (42 × 0.4 × 20)
= 8736 + 336 = 9072 J
Total heat energy gained
= (336 × x) + (x × 4.2 × 10)
= 336x + 42x = 378x
By principle of calorimetry,
Heat lost = Heat gained
378x = 9072
x = \(\frac{9072}{378}\) = 24 g
Question 10.
(a) Draw a neat labeled diagram of an A.C. generator. [3]
Answer:
The diagram is shown :
(b) (i) Define nuclear fission. [3]
(ii) Rewrite and complete the following nuclear reaction by filling in the atomic number of
Ba and mass number of Kr :
Answer:
(i) It is the splitting of a heavy nucleus into two or more smaller nuclei with the release of tremendous energy.
(ii)
(c) The diagram below shows a magnetic needle kept just below the conductor AB which is kept in North South direction. [4]
(i) In which direction will the needle deflect when the key is closed?
(ii) Why is the deflection produced?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB?
(iv) Name one device which work on this principle.
Answer:
(i) East.
(ii) A current carrying conductor produces a magnetic field around itself.
(iii) The direction of deflection will reverse. (Towards west)
(iv) An electromagnet.