ICSE Class 10 Physics Important Questions 2027 (Repeated in Board Exams)

A metal rod AB of length 80 cm is balanced at 45 cm from the end A with 100 gf weights suspended from the two ends. If this rod is cut at the centre C, then compare the weight of AC to the weight of BC. (Use >, < or =)

Give a reason for your answer in (a) [comparison of the weights of AC and BC].

Two bags are suspended from ropes at P and Q on a wheel that can rotate around O; the wheel remains in equilibrium. State with a reason who is carrying the heavier bag.

The diagram shows wheel O pivoted at point A. Three equal forces F1, F2 and F3 act at point B on the wheel. Which force will produce maximum moment about A?

A moment of couple has a tendency to rotate the body in an anticlockwise direction. The moment of couple is taken as: (a) positive (b) negative (c) maximum (d) zero

ABCDE is a regular pentagon with its centre of gravity (CG) at O. What will be the most probable position (W, X, Y, Z or O) of the new centre of gravity if a piece of clay is attached at point A?

What will be the most probable position of the new centre of gravity if the pentagon is cut along the line PQ (CG of the remaining part DCBQPE)?

Complete by choosing the correct answer: Friction acts __________ [tangential / radial] to a car undergoing circular motion.

State two factors on which the position of Centre of Gravity of a body depends.

Three levers X, Y, Z of equal lengths are shown. Which class of lever do these belong to?

Given two pulleys, copy and complete the labelled diagram connecting the two pulleys with a tackle to obtain Velocity Ratio = 2.

State whether the work done by gravity is positive, negative, or zero: a person walks on a levelled road.

State whether the work done by gravity is positive, negative, or zero: a person climbs a ladder.

State whether the work done by gravity is positive, negative, or zero: a car in a neutral gear is coming down the slope.

Richa weighing 40 kgf leaves point P on her skateboard and reaches point Q on the ground with velocity 10 ms^-1. Calculate the kinetic energy of Richa at point Q.

The kinetic energy of a given body depends on the: (a) position (b) centre of gravity (c) momentum (d) displacement

During power production in a coal-based thermoelectric power plant, the correct sequence of energy conversions taking place is: (a) heat -> mechanical -> chemical (b) heat -> mechanical -> electrical (c) chemical -> heat -> light (d) heat -> chemical -> electrical

Match the movement of the body part to the class of lever: Nodding head.

Match the movement of the body part to the class of lever: Lifting body weight on your toes.

Based on the lever arrangement identified in part (a), calculate the maximum mechanical advantage using the distances shown.

Complete by choosing the correct answer: If the mass as well as the velocity of a body is doubled then the kinetic energy of the body __________ [is doubled / becomes eight times / becomes four times] the initial kinetic energy.

Complete by choosing the correct answer: A ___________ [Class II / Class III] lever will always have M.A. > 1.

Calculate the potential energy gained by a load of 100 kgf lifted by this pulley to a height of 5 m. (g = 10 ms^-2)

The energy transformation taking place during photosynthesis in plants is: (a) heat to chemical (b) chemical to light (c) light to chemical (d) chemical to heat

The Velocity Ratio (V.R.) of a block and tackle system of three pulleys with the effort in upward direction is: (a) 1 (b) 2 (c) 3 (d) 4

If Load = 48 kgf and efficiency is 80% then calculate: 1. Mechanical Advantage. 2. Effort needed to lift the load.

A bar of length 120 cm is used as a lever to raise a load placed at point P. Seven equidistant points P, Q, R, S, T, U, V are marked 20 cm apart. Specify the fulcrum and effort points that yield the greatest mechanical advantage.

Calculate the speed of the ball at which it hits the ground. [g = 10 m/s²]

Draw a graph of potential energy vs height for a body thrown vertically upwards. [Assume no friction is present.]

A simple pendulum of mass 200 g is displaced from mean position A to extreme position B, being raised by 5 m; potential energy at A is zero. What is the potential energy of the pendulum at position B? (g = 10 ms^-2)

What is the total mechanical energy at point C?

What is the speed of the bob at position A when released from B? (Take g = 10 ms^-2, no loss of energy.)

The adjacent diagram shows the movable block of a block and tackle system with effort in a convenient direction. From the diagram we can conclude that the number of pulleys used in the fixed block are ___________. (a) 1 (b) 3 (c) 2 (d) 4

The diagram shows a block and tackle system. Copy and complete the labelled diagram showing the correct connection of the tackle and the direction of the forces involved to obtain maximum V.R. with the convenient direction.

A ball of mass 20 g falls from a height of 45 m and rebounds to a height of 40 m. Calculate the initial potential energy of the ball. [g = 10 m/s²]

Sumit does 600 J of work in 10 min and Amit does 300 J of work in 20 min. Calculate the ratio of the powers delivered by them.

A glass lens always forms a virtual, erect, and diminished image of an object kept in front of it. Identify the lens.

Advanced optical sensors in missiles use fibre optic cables to transmit light signals with minimal loss. Name the optical phenomenon that allows light signals to remain confined within the fibre optic cables during transmission.

A lens is made of two materials of different refractive indices (μ1, μ2) as shown. If the rays are coming from a distant object, then how many images will be formed?

Redraw the diagram and complete the path of the light ray AB through the glass prism till it emerges out of the prism. Critical angle of the glass is 42°.

The diagram shows a fish in the tank and its image seen on the surface of water. Name the phenomenon responsible for the formation of this image.

An object is placed at a distance of 24 cm in front of a convex lens of focal length 8 cm. What is the nature of the image so formed?

Calculate the distance of the image from the lens.

List the two main conditions necessary for this phenomenon to occur.

The refractive index of water is 1.33 at a certain temperature. When the temperature of water is increased by 40°C, the refractive index changes to 'x'. State whether x < 1.33 or x > 1.33.

A rectangular glass block of refractive index 1.5 has an air bubble trapped inside it; when seen from surface AB it appears to be 4 cm deep. Calculate the actual depth of the air bubble from the surface AB.

A convex lens with a focal length of 12 cm has an object at a distance of 20 cm in front of the lens. A blurred image is obtained on the screen placed at a distance of 23 cm in front of the lens. In order to obtain a clear image, the screen has to be moved: (a) towards the lens. (b) away from the lens. (c) to a position very far from the lens. (d) either towards or away from the lens.

A double convex lens with refractive index μ1 is placed inside two liquids of refractive indices μ2 and μ3, with μ2 > μ1 and μ1 > μ3. How would a parallel incident beam of light refract when it comes out of the lens in each of the cases: (1) in Figure a (2) in Figure b?

As the ray of light travels from medium 1 to medium 2, how does the wavelength of light change? (State whether it increases, decreases, or remains constant.)

A candle and a screen are placed 90 cm apart. A lens is placed between them such that a clear image is formed on the screen and the image is twice the size of the object. Which type of lens is used?

State two differences between normal reflection and total internal reflection.

The diagram shows that an observer sees the image of an object O at I through a glass block. Name and define the phenomenon responsible for seeing the image at a different position.

State the effect on X (apparent shift) when: 1. Y (thickness) increases 2. Y decreases.

An object is placed in front of a concave lens at a distance of 45 cm from it. If its image is formed at a distance of 30 cm from the lens, calculate the focal length of the lens.

Small air bubbles rising up a fish tank appear silvery when viewed from some particular angle is due to the: (a) reflection (b) refraction (c) dispersion (d) total internal reflection

Linear magnification (m) produced by a concave lens is: (a) m < 1 (b) m > 1 (c) m = 1 (d) m = 2

Name the invisible radiation which is studied using the quartz prism.

Assertion (A): Blue light scatters more than red light in the atmosphere. Reason (R): Intensity of scattered light is inversely proportional to the fourth power of wavelength. (a) (A) is true and (R) is false. (b) (A) is false and (R) is true. (c) Both (A) and (R) are true, and (R) is the correct explanation of (A). (d) Both (A) and (R) are true, but (R) is not the correct explanation of (A).

If red, blue, green and yellow lights are allowed to enter the same glass block with the same angle of incidence (∠i), then for which colour will the angle of deviation be the greatest? (a) blue (b) green (c) yellow (d) red

A mixture of red, blue, and green light rays is passed through a convex lens. State whether the ray passes through a single point or through different points on the principal axis after refraction.

Name one type of radiation with a wavelength greater than that of the radiation mentioned by you in (b) above.

Inside the prism, during the dispersion of white light, compared to blue, red light: (a) slows down less and refracts more. (b) slows down more and refracts less. (c) slows down more and refracts more. (d) slows down less and refracts less.

State one use of the radiation mentioned by you in (b) above.

Assertion (A): Infrared radiations travel long distance through a dense fog and mist. Reason (R): Infrared radiations undergo minimal scattering in earth's atmosphere. (a) both A and R are true and R is the correct explanation of A. (b) both A and R are True and R is not the correct explanation of A. (c) assertion is false but reason is true. (d) assertion is true but reason is false.

If instead of sunlight, a green-coloured ray is passed through a glass prism, what will be the colour of the emergent ray?

Speed of blue light in water is: (a) more than green light (b) more than orange light (c) more than violet light (d) more than red light

Which one of the following combinations is the correct ascending order of electromagnetic waves in terms of wavelength? (a) gamma-rays, visible light, microwaves (b) microwaves, visible light, gamma-rays (c) gamma-rays, microwaves, visible light (d) microwaves, gamma-rays, visible light

Name one property common to all electromagnetic radiations.

Name the radiation which is used in traffic signals in India.

Two sound waves, X and Y have the same amplitude and the same wave pattern, but their frequencies are 60 Hz and 120 Hz respectively, then: (a) X will be shriller, and Y will be grave. (b) X will be grave, and Y will be shriller. (c) X will differ in quality than Y. (d) X will be louder than Y.

A person standing in front of a cliff fires a gun and hears its echo after 3 s. Speed of sound in air is 336 ms^-1. Calculate the distance of the person from the cliff.

After moving a certain distance from the cliff, he fires the gun again and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person has moved.

Name the wave used for echo depth sounding.

Give one reason why the waves mentioned in (a) are used for the above purpose.

A mother pushes her daughter on a swing going through positions A, B, C (A and C extreme, B mean). Which is the right position (A, B or C) for the mother to give a constant periodic push in the forward direction to increase the amplitude of the swing?

Name the phenomenon involved in this.

On the basis of this example, explain how this phenomenon helps to increase the amplitude of the swing.

Name the important characteristic of sound that is affected during this phenomenon.

A boy tunes a radio channel to a radio station 93.5 MHz. Name and define the scientific wave phenomenon involved in tuning the radio channel.

Two sound boxes A and B have wires of same length (l) and tension (10 kgf) but different cross-sectional areas. Vibrating tuning forks of frequency 300 Hz are placed on the boxes; the paper rider falls off in case of B but not in case of A. Name and explain the phenomenon responsible for the falling off of the paper rider in B.

A loud sound is heard from wire A when the experiment is repeated using a tuning fork of frequency 'f'. Is 'f' greater than, less than or equal to 300 Hz? Justify your answer.

One end of a plastic foot ruler is held tightly at the edge of a table and the other end is plucked. Name the vibrations produced in the ruler.

Complete by choosing the correct answer: The minimum distance for distinct echo formation is __________ [greater / lesser] in water as compared to air.

When the stem of vibrating tuning fork is pressed on a table, the tabletop starts vibrating. These vibrations are definitely an example of: (a) resonance (b) natural vibrations (c) forced vibrations (d) damped vibrations

Convert 93.5 MHz to SI unit.

Complete by choosing the correct answer: Quality of sound depends on its ___________ [amplitude / waveform].

State one way to increase the frequency of these vibrations.

A submarine in the sea sends an ultrasonic ping and a stopwatch is started simultaneously. The stopwatch stops on receiving the reflected wave from an obstacle and reads 1 minute 40 seconds. Calculate the distance of the obstacle from the submarine. (Speed of sound in water 1500 ms^-1.)

According to the old convention, the colour of the earth wire is: (a) black (b) green (c) yellow (d) red

Compare (> or < or =) the specific resistance in both cases.

Tim wants to connect a fuse to his oven and control it from two different locations, as shown in the circuit diagram. Which one of the two, A or B, should be a live wire?

An appliance with a metal covering, rated at 2 kW, 220 V, is to be connected in a circuit. Given two diagrams (R and S) depicting different circuit configurations, identify the safest circuit.

Calculate the current through the 3 Ω resistance when the circuit is complete.

Complete by choosing the correct answer: Two copper wires can have different resistivity if they have different __________ [lengths / temperatures].

The image displays kilowatt-hour meter readings recorded at two distinct points in time. Assuming a continuously running 2000 W air conditioner as the sole electrical device in use, calculate the time interval, in hours, between these two meter readings.

Write two reasons, supported by mathematical calculations where applicable, to justify your choice of the safest circuit.

A Nichrome wire X with length (l) and cross-sectional area (A) is connected to a 10 V source and another Nichrome wire Y with length (2l) and cross-sectional area (A/2) is connected to a 20 V source. Compare the resistances of wires X and Y. [Given the resistivity of Nichrome is ρ.]

Compare the electrical power consumed by each wire.

Compare the masses of these wires. [Given the density of nichrome is d.]

State True or False: Wire X and wire Y both show the same rise in temperature at the same time.

Three bulbs of powers P1, P2 and P3 (P1 < P2 < P3) are connected in a certain way such that P3 glows the brightest. What type of connection exists between these bulbs?

Compare the voltages (V1, V2, V3) across these bulbs. (Use >, < or =)

Will the circuit still function if one of the bulbs is fused?

A circuit is used for studying Ohm's Law using a glass tube filled with mercury (tube 1) connected through electrodes E1 and E2; the experiment is repeated with tube 2 which the same amount of mercury fills. Neglecting internal resistance, use (> or < or =) to compare the resistance in both cases.

Compare (> or < or =) the voltmeter readings in both cases.

What is the meaning of the statement that the bulb is rated 600 W, 220 V?

The graph of voltage vs current for four different materials is shown. Which of these four materials would be used for making filament of a bulb? (a) Q (b) S (c) P (d) R

In the circuit given below, identify the correct relation between the currents flowing through the 2 Ω, 3 Ω, and 5 Ω resistors: (a) current through 2Ω > current through 3Ω (b) current through 5Ω < current through 3Ω (c) current through 2Ω = current through 5Ω (d) current through 5Ω > current through 3Ω

Observe the given circuit diagram (2 Ω in parallel with series 5 Ω and 3 Ω, cell 4 V, 0.4 Ω, key K). Calculate the resistance of the circuit when the key K completes the circuit.

Study the circuit diagram. Calculate the total resistance of the circuit.

An electric iron rated 1100 W, 220 V is operated for 5 hours. Calculate the minimum rating of the fuse required.

Identify the option that displays the correct wiring with correct colour code: (a) (b) (c) (d) [diagram options]

If the bulb B3 is removed from the circuit, then will the brightness of the bulb B1 increase, decrease or remain the same?

In a closed circuit containing a bulb and a cell, the electromotive force (ε) and the terminal voltage (V) is related as (I is current, r is internal resistance): (a) V = ε + Ir (b) V = ε - Ir (c) V = ε ÷ Ir (d) V = ε x Ir

The specific resistance of a conductor depends on its: (a) length (b) material (c) area of cross section (d) radius

For the given circuit, calculate the current I drawn from the cell.

A copper wire is wound around a U-shape soft iron bar. An iron pin is brought near the arrangement. First Source P and then Source Q are connected across AB, each operating independently. State True or False: Source P as well as Source Q, when connected across AB, can attract the iron pin.

Justify your answer to (a) with a suitable reason.

Name the law used to determine the direction of motion of PQ.

A transformer is used to change a high alternating e.m.f. to a low alternating e.m.f. of the same frequency. Identify the type of transformer used for the above purpose.

State whether the turns ratio of the above transformer is =1 or >1 or <1.

A magnet is released along the axis of a copper coil. State the polarity at the top end of the coil when the magnet leaves the coil.

Name the law which can be used to determine the direction of the induced current in the coil.

A wire bent in the form of a loop passes through a cardboard on which iron filings are kept; when current flows the filings arrange as shown with the direction of the magnetic field. State the polarities of the battery at A and B.

State the effect on the magnetic field if an iron rod is held along the axis of the coil.

State one way to: 1. change the polarity of the coil. 2. decrease the strength of the magnetic field around the coil.

State one factor that affects the magnitude of induced current in an AC generator.

Mention the temperature range in which the substance is in its liquid state.

The amount of heat energy required to melt a given mass of a substance at its melting point, without any rise in its temperature is called the: (a) specific heat capacity (b) specific latent heat of fusion (c) latent heat of fusion (d) heat capacity

The diagram shows a cooling curve for a substance X. State the temperature at which the substance condenses.

30 g of ice at 0°C is used to bring down the temperature of a certain mass of water at 70°C to 20°C. Find the mass of water. [Specific heat capacity of water = 4.2 Jg^-1°C^-1 and specific latent heat of ice = 336 Jg^-1.]

Heat capacity of a body is the: (a) energy needed to melt a body without change in its temperature. (b) energy needed to raise the temperature of a body by 1°C. (c) increase in volume of the body when its temperature increases by 1°C. (d) total amount of internal energy that is constant.

A solid of mass 60 g at 100°C is placed in 150 g of water at 20°C. The final steady temperature is 25°C. Calculate the heat capacity of the solid. [sp. heat capacity of water = 4.2 J g^-1 K^-1]

Why do we prefer ice to ice-cold water for cooling a drink?

Complete by choosing the correct answer: The CGS unit of specific heat capacity is _________ [erg g^-1 K^-1 / cal g^-1 K^-1].

State True or False: The amount of heat released when a substance is cooled by 10°C in its liquid state is greater than the heat released when it is cooled by the same amount in its solid state.

To measure the temperature of the flame of a Bunsen burner, a lump of copper of mass 0.12 kg is heated on the flame for a long time. The copper is quickly transferred into a beaker of negligible heat capacity containing 0.84 kg of water and the temperature of the water rose from 15°C to 35°C. Calculate the temperature of the flame. [sp. heat capacity of copper = 0.4 Jg^-1°C^-1, sp. heat capacity of water = 4.2 Jg^-1°C^-1]

Each of the substances given below is supplied with the same amount of heat. Which one will attain the highest temperature? Lead (0.031), Aluminium (0.21), Copper (0.095), Iron (0.115) cal/g°C. (a) Aluminium (b) Copper (c) Iron (d) Lead

A metallic wire is stretched in such a way that its new length becomes twice the original length. How does its specific heat capacity change? (a) becomes double (b) becomes 4 times (c) becomes 1/4 (d) remains the same

Complete by choosing the correct answer: Heat absorbed during change of phase depends on __________ [mass / change in temperature / specific heat capacity] of the substance.

Which material, X or Y, would you select to make a calorimeter?

Atmospheric temperature after a hailstorm is greater than the temperature during the hailstorm. State True or False.

State the principle of Calorimetry.

Calculate the amount of heat absorbed by 200 g of paraffin wax to melt completely at its melting point. [Specific latent heat of fusion of paraffin wax = 146 Jg^-1]

Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C. (Specific latent heat of ice = 336 J g^-1, specific heat capacity of water = 4.2 J g^-1 °C^-1)

A metal piece of mass 5 g has thermal capacity 2.5 JK^-1. If the mass of the metal is tripled, then its specific heat capacity will be: (a) 7.5 JK^-1 (b) 2.5 JK^-1 (c) 1.5 Jg^-1K^-1 (d) 0.5 Jg^-1K^-1

A nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission? (a) protons = 93, neutrons = 142 (b) protons = 95, neutrons = 144 (c) protons = 93, neutrons = 144 (d) protons = 95, neutrons = 142

Name the radiation that is emitted during the decay of a nucleus that has the highest penetrating power.

Does the emission of the above-mentioned radiation result in a change in the mass number?

When {}⁶Li₃ is bombarded with a neutron, it produces {}⁴He₂ and an isotope of hydrogen. Write the notation for the hydrogen isotope formed.

What is the general name of the elements X and Y?

If the atomic number of Y is 80 then what is the atomic number of X?

A graph shows number of protons (x-axis) vs number of neutrons (y-axis) for elements A, B, C, D, E. Identify the radioactive radiation emitted when element C decays into element E. Represent this using a nuclear reaction.

What is the special name given to elements like D and E?

If element C transforms into element B by emitting a radioactive ray, how will this ray behave in an electric field?

Which element is used in the lining of the special aprons worn by workers in nuclear power plants?

A radioactive nucleus X emits an alpha particle followed by two beta particles to form nucleus Y. With respect to the element X, where would you position the element Y in the periodic table?

Which point on the graph indicates the daughter nucleus after Cm undergoes radioactive decay of 1 α followed by 2 β?

Copy and complete the following nuclear reaction: {}²²²₈₆Rn → {}²¹⁸₈₄Po + {}^___{__}X

What will be the effect on the radiation X, emitted in the above reaction, when it is allowed to pass through an electric field?

State the mass number of the daughter nucleus.

Complete by choosing the correct answer: ___________ radiation deviates minimum in a magnetic field. [Alpha / Beta].

Complete by choosing the correct answer: The nuclear radiation with lowest ionizing power is __________ [α / β / γ].

A radioactive element is placed in an evacuated chamber. Then the rate of radioactive decay will: (a) Decrease (b) Increase (c) Remain unchanged (d) Depend on the surrounding temperature

Complete the following radioactive reaction: {} X → Y + 2 {}⁴He → {}²³⁴₉₁Z + {}⁰_-1e