ICSE Class 6 Physics Sample Paper with Solutions Set 02

Question 1
Choose the correct answer out of the four available choices given under each question. [15]

1. If two unequal forces are applied on an object in opposite directions, then [1 Mark]
(a) these forces will add to one another
(b) these forces will cancel each other
(c) the net force will be the difference between the two forces
(d) these forces will multiply each other

Answer: (c) the net force will be the difference between the two forces

When two unequal forces act in opposite directions, the smaller force subtracts from the larger force, resulting in a net force equal to their difference acting in the direction of the larger force.

Teacher's Note:
a) Remember that forces acting in opposite directions oppose each other.
b) Students often confuse this with forces acting in the same direction, which simply add up.

2. When a person speaks in front of a microphone, sound energy is converted into [1 Mark]
(a) Loud sound energy
(b) Magnetic energy
(c) Chemical energy
(d) Electric energy

Answer: (d) Electric energy

A microphone acts as a transducer that converts sound waves (sound energy) into electrical signals (electric energy).

Teacher's Note:
a) Note the energy transformation principle involved in common acoustic devices.
b) Do not confuse a microphone (sound to electricity) with a loudspeaker (electricity to sound).

3. Which of the following is not used for measuring time? [1 Mark]
(a) Sundial
(b) Water clock
(c) Sand clock
(d) Hand span

Answer: (d) Hand span

A hand span is a traditional unit and non-standard measure for length, not time.

Teacher's Note:
a) Sundials, water clocks, and sand clocks are ancient devices specifically designed to measure elapsed time.
b) Ensure clear distinction between physical quantities like length, mass, and time along with their measuring tools.

4. Efficiency of a machine is [1 Mark]
(a) output \times input
(b) output / input
(c) input / output
(d) output + input

Answer: (b) output / input

Efficiency is defined as the ratio of useful work output to the total work input.

Teacher's Note:
a) Efficiency is always a ratio or percentage comparing output energy or work to input energy or work.
b) Students often invert the ratio as input divided by output.

5. In which direction does a freely suspended compass needle align itself? [1 Mark]
(a) South-North
(b) North-South
(c) East-West
(d) West-East

Answer: (b) North-South

A freely suspended magnet or compass needle always comes to rest pointing approximately along the geographic North-South direction due to Earth's magnetic field.

Teacher's Note:
a) The magnetic north pole of the compass needle points towards the geographic north region.
b) Always state the direction precisely as North-South or geographic north-south.

6. What is the unit of force? [1 Mark]
(a) N/m
(b) Nm
(c) N²
(d) N

Answer: (d) N

The standard S.I. unit of force is the Newton, represented by the symbol N.

Teacher's Note:
a) One Newton is the force required to give a mass of \( 1 \, \text{kg} \) an acceleration of \( 1 \, \text{m/s}^2 \).
b) Nm represents Newton-metre, which is the unit of work or torque, not force.

7. Why do trucks carrying heavy loads have eight tyres instead of four? [1 Mark]
(a) To increase the area of contact
(b) To decrease the area of contact
(c) To increase friction
(d) To decrease friction

Answer: (a) To increase the area of contact

Increasing the number of tyres increases the total area of contact with the ground, which reduces the pressure exerted on the road surface.

Teacher's Note:
a) Pressure is inversely proportional to the area of contact for a given force (\( P = F/A \)).
b) Students frequently confuse the effect of area on pressure with its effect on friction.

8. Which of the following is NOT used to reduce friction? [1 Mark]
(a) Lubricant
(b) Wheels
(c) Boric powder
(d) Cleats

Answer: (d) Cleats

Cleats are spiked or textured projections on shoes or tyres designed to increase friction and prevent slipping.

Teacher's Note:
a) Lubricants, wheels, and boric powder act as anti-friction agents.
b) Cleats and treads are specifically used where high traction and grip are required.

9. The 'nodding action of the human head' is an example of which class of lever? [1 Mark]
(a) Class I
(b) Class II
(c) Class III
(d) None of the above

Answer: (a) Class I

In the nodding action of the human head, the spine acts as the fulcrum located between the load (front part of the head) and the effort (muscles at the rear of the neck), forming a first class lever.

Teacher'sNote:
a) Identify the positions of fulcrum, load, and effort to classify levers correctly.
b) Class I levers have the fulcrum situated between the effort and the load.

10. Class II levers are designed to have [1 Mark]
(a) M.A. = V.R.
(b) M.A. > V.R.
(c) M.A. > 1
(d) M.A. < 1

Answer: (c) M.A. > 1

In a second class lever, the load is between the fulcrum and the effort, making the effort arm longer than the load arm, which results in a Mechanical Advantage greater than 1.

Teacher's Note:
a) Class II levers act as force multipliers, allowing a smaller effort to overcome a larger load.
b) Remember that Mechanical Advantage equals effort arm divided by load arm.

11. Lodestone is an example of a/an [1 Mark]
(a) Artificial magnet
(b) Electromagnet
(c) Natural magnet
(d) None of the above

Answer: (c) Natural magnet

Lodestone is a naturally occurring magnetic iron ore ( magnetite ) that exhibits magnetic properties.

Teacher's Note:
a) Natural magnets are found in nature and possess permanent magnetism without human intervention.
b) Artificial magnets are manufactured by humans using iron, steel, or alloys.

12. In Class I lever the [1 Mark]
(a) Fulcrum is between the load and effort
(b) Load is between the load and fulcrum
(c) Effort is between the load and fulcrum
(d) None of the above

Answer: (a) Fulcrum is between the load and effort

By definition, a first class lever has its fulcrum positioned anywhere between the applied effort and the load.

Teacher's Note:
a) Common examples of first class levers include scissors, crowbars, and seesaws.
b) Emphasize the central position of the fulcrum for this class.

13. The force exerted by a magnet is called [1 Mark]
(a) Gravitational force
(b) Magnetic force
(c) Mechanical force
(d) Muscular force

Answer: (b) Magnetic force

Magnetic force is the non-contact force exerted by magnets on magnetic materials like iron, nickel, and cobalt, or between magnetic poles.

Teacher's Note:
a) Magnetic force can be both attractive and repulsive.
b) It is classified as a non-contact field force.

14. A nut cracker is an example of a ____________ lever. [1 Mark]
(a) First order
(b) Second order
(c) Third order
(d) None of the above

Answer: (b) Second order

In a nutcracker, the nut (load) is placed in the middle between the fulcrum (the hinge at the end) and the effort applied at the handles, making it a second order lever.

Teacher's Note:
a) Second order levers always have the load situated between the fulcrum and the effort.
b) Examples include wheelbarrows, bottle openers, and nutcrackers.

15. For doing more work, more ___________ has to be applied. [1 Mark]
(a) Energy
(b) Displacement
(c) Force
(d) None of the above

Answer: (c) Force (Note: The official key lists (c), though energy is also directly related; keeping option (c) as per the official marking scheme.)

Performing a larger amount of work requires a greater magnitude of force applied over a distance, or alternatively more energy expended.

Teacher's Note:
a) Work is defined as force multiplied by displacement in the direction of the force.
b) The official key marks option (c) as correct in the context of elementary force application.

Question 2

(A) Name the following. [5 Marks]
1. The ultimate source of energy. [1 Mark]
2. Force which does not require physical contact between the two bodies on which it acts. [1 Mark]
3. The ratio of load to effort. [1 Mark]
4. A grooved wheel which is used along with a rope or a chain. [1 Mark]
5. Unit of thrust. [1 Mark]

Answer:
1. Sun
2. Non-contact force
3. Mechanical Advantage (M.A. = Load / Effort)
4. Pulley
5. Newton

Teacher's Note:
a) Ensure terminology is precise for scientific definitions.
b) Thrust is a force, hence its S.I. unit is Newton.

(B) Fill in the blanks. [5 Marks]
1. A quantity which can be measured is called a __________ quantity. [1 Mark]
2. _______________ forces require physical contact between the objects. [1 Mark]
3. ________________ is an instrument used to find the directions at a place. [1 Mark]
4. Force acting on a body perpendicular to its surface is called _______________. [1 Mark]
5. ______________ is the total energy of motion and position of an abject. [1 Mark]

Answer:
1. Physical
2. Contact
3. Magnetic compass
4. Thrust
5. Mechanical energy

Teacher's Note:
a) Mechanical energy is the sum of kinetic energy (motion) and potential energy (position).
b) Check spelling for technical terms like physical and mechanical.

Question 3

(A) Match the following. [5 Marks]

Answer:
1. Beam balance - c. Measurement of mass
2. Rubbing a glass rod with silk cloth - d. Charging by friction
3. Horse-shoe magnet - e. Artificial magnet
4. Burning of a candle - b. Chemical energy
5. Self-demagnetisation - a. Magnetic keepers

Teacher's Note:
a) Match items based on fundamental scientific applications and principles.
b) Magnetic keepers prevent self-demagnetisation of artificial magnets by completing the magnetic circuit.

(B) Correct the following sentences. [5 Marks]
1. Powder applied on a carrom board increases friction. [1 Mark]
2. Magnetic force is the weakest of all the forces. [1 Mark]
3. Natural magnets are stronger than artificial magnets. [1 Mark]
4. The time period of the simple pendulum depends on the mass of the bob used. [1 Mark]
5. Moon is the ultimate source of energy. [1 Mark]

Answer:
1. Powder applied on a carrom board reduces friction.
2. Gravitational force is the weakest of all the forces.
3. Artificial magnets are stronger than natural magnets.
4. The time period of a simple pendulum does not depend on the mass of the bob used but on the length of the pendulum.
5. Sun is the ultimate source of energy.

Teacher's Note:
a) Statement correction questions test conceptual clarity by identifying incorrect terms.
b) Ensure students rewrite the complete correct sentence rather than just single words.

Question 4

(A) Answer the following.
1. Differentiate between mass and weight. [4 Marks]

Answer:

Teacher's Note:
a) Differentiate points clearly on definition, unit, measuring device, and constancy.
b) Students often confuse mass with weight in daily conversation.

2. Define force. [1 Mark]

Answer:
A force is that physical quantity which changes or tends to change the state of rest or uniform motion of a body, or changes its shape and size.

Teacher's Note:
a) Include both state of motion and shape change in the definition for completeness.
b) Force is a vector quantity having magnitude and direction.

(B) What are the uses of an electromagnet? [5 Marks]

Answer:
1. They are used in devices such as electric bells, telegraph sounders, telephone receivers, motors, and generators.
2. Electromagnets are used in electrical measuring instruments such as galvanometers, ammeters, and voltmeters.
3. Huge electromagnets are used for loading and unloading heavy loads of scrap iron and other iron objects at shipyards and factories.
4. They are used by eye specialists to remove small pieces of iron or steel lodged accidentally in patients' eyes.

Teacher's Note:
a) List at least four clear practical applications for full marks.
b) Emphasize that electromagnets are temporary magnets whose magnetism can be controlled by electric current.

Question 5

(A) Answer in one sentence: [5 Marks]
1. Define: Light year. [1 Mark]
2. Give three names of simple machines which are of lever type. [1 Mark]
3. Which is the most important, inexhaustible and main source of energy? [1 Mark]
4. What is meant by the term magnetic field? [1 Mark]
5. Give two examples of muscular force. [1 Mark]

Answer:
1. The distance travelled by light in one year in vacuum is called one light year.
2. Pliers, hammers, and nutcrackers are simple machines of lever type.
3. The Sun is the most important, inexhaustible, and main source of energy.
4. The space around a magnet where its magnetic influence is experienced is called the magnetic field.
5. Examples of muscular force include animals pulling carts (such as bullocks or reindeers pulling sledges) and humans lifting heavy objects.

Teacher's Note:
a) Keep answers concise and strictly limited to one sentence as requested.
b) Light year is a unit of astronomical distance, not time.

(B) Find the odd one out. [5 Marks]
1. Diesel, petrol, kerosene, photocell [1 Mark]
2. Beam balance, stopwatch, grocer's balance, digital balance [1 Mark]
3. Ice tongs, claw hammer, crowbar, see-saw [1 Mark]
4. Steel, copper, aluminium, brass [1 Mark]
5. Using lubricants, using ball-bearings, polishing the surfaces, making grooves in tyres [1 Mark]

Answer:
1. Photocell - Photocell converts light energy to electrical energy whereas diesel, petrol, and kerosene are fossil fuels that release chemical energy.
2. Stopwatch - Stopwatch measures time, whereas all others are balances used for measuring mass.
3. Ice tongs - Ice tongs are a third-class lever, whereas the others are first-class levers.
4. Steel - Steel is a magnetic substance, whereas the others are non-magnetic substances.
5. Making grooves in tyres - Making grooves in tyres increases friction, whereas all the others are methods used to reduce friction.

Teacher's Note:
a) Always state the exact reason for identifying the odd one out.
b) Check classification criteria across categories such as materials, friction methods, and simple machines.

Question 6

(A) How can a magnet be demagnetised? [5 Marks]

Answer:
A magnet can be demagnetised by the following methods:
1. By hammering the magnet repeatedly.
2. By handling it roughly or dropping it repeatedly on a hard surface.
3. By heating the magnet to a very high temperature or storing it incorrectly along the East-West direction.
4. By passing an alternating current around the magnet in a solenoid.
5. Through self-demagnetisation, which occurs when magnets are stored without magnetic keepers with their poles left free.

Teacher's Note:
a) Demagnetisation destroys or weakens the alignment of magnetic domains inside a magnet.
b) List at least four clear methods for full marks.

(B) Define the following. [5 Marks]
1. Input or input energy [1 Mark]
2. Temporary magnet [1 Mark]
3. Laboratory thermometer [1 Mark]
4. Magnetic force [1 Mark]
5. Length of a magnet [1 Mark]

Answer:
1. Input or input energy: The amount of work done on a machine or the energy supplied to the machine.
2. Temporary magnet: A magnet that loses its magnetic properties as soon as the magnetising force or current is removed.
3. Laboratory thermometer: An instrument used to measure the temperature or temperature changes of substances, generally having a range from -10°C to 110°C.
4. Magnetic force: The attraction or repulsion exerted between the poles of magnets or between a magnet and magnetic materials.
5. Length of a magnet: The total distance between its North Pole and its South Pole (geometrically measured or between its effective poles).

Teacher's Note:
a) Definitions must be scientifically precise and clear.
b) Note the standard temperature range for laboratory thermometers.

Question 7

(A) Answer the following.
1. Give two advantages of an electromagnet. [2 Marks]

Answer:
1. An electromagnet can be easily magnetised and demagnetised by turning the electric current on or off.
2. The strength of an electromagnet can be made much greater than that of any permanent magnet by increasing the current or number of turns in the coil.

Teacher's Note:
a) Highlight the controllable nature of electromagnets compared to permanent magnets.
b) State both points clearly for full marks.

2. What is a machine? [3 Marks]

Answer:
A machine is a device which is used to make our work easier or faster by:
1. Transmitting force from one point to another.
2. Changing the direction of applied force.
3. Gaining speed.
4. Overcoming a large resistive load by applying a relatively smaller effort.

Teacher's Note:
a) Define the primary function of simple machines clearly.
b) Mention at least two or three specific mechanical advantages provided by machines.

(B) Answer the following.
1. Write four advantages of friction. [2 Marks]

Answer:
1. Friction enables us to walk and run without slipping.
2. Friction enables us to write and draw on paper using pencils or pens.
3. Friction enables us to strike and burn a matchstick.
4. Friction enables vehicles to stop safely when brakes are applied.

Teacher's Note:
a) Although friction causes wear and tear, it is essential for most daily movements.
b) Provide four distinct, concise points.

2. Explain how to prepare a magnet by the magnetic induction method. [3 Marks]

Answer:
1. Place a long iron nail on the arm of a stand and spread some iron pins on the base below it; initially, the pins are not attracted to the nail.
2. Touch a strong bar magnet to the head of the nail; the iron pins at the base will now cling to the pointed end of the nail because the nail has temporarily acquired magnetic properties.
3. When the bar magnet is removed from the head of the nail, the pins fall down, demonstrating temporary magnetization and demagnetism. This property by which an ordinary piece of iron acquires magnetism in the presence of a magnet is called magnetic induction.
[Figure: Diagram of a stand holding a vertical iron nail above a pile of iron pins, showing pins clinging to the nail when a bar magnet touches its head, and falling off when the magnet is removed.]

Teacher's Note:
a) Explain the step-by-step procedure clearly.
b) Emphasize that magnetic induction is temporary unless a magnetic material like steel is used to create permanent magnets.