Paper 1 : Definitions

Question 1

What is normal force?

Answer 1

Normal force, N, is the force or component of a force which a surface exerts on an object in contact, perpendicular to the surface.

Question 2

What is frictional force?

Answer 2

Frictional force, f, is the force that opposes the motion of an object and acts parallel to the surface.

Question 3

What is static frictional force?

Answer 3

Static frictional force, fs, is the force that opposes the tendency of motion of a stationary object relative to a surface.

Question 4

What is kinetic frictional force?

Answer 4

Kinetic frictional force, fk, is the force that opposes the motion of a moving object relative to a surface.

Question 5

What is Newton’s first law of motion?

Answer 5

A body will remain in its state of rest or motion at constant velocity unless a non-zero resultant/net force acts on it.

Question 6

Why is it important to wear seatbelts?

Answer 6

Wearing seatbelts is important because, according to Newton’s first law, a body in motion will continue in motion unless acted upon by a force.

Question 7

What is Newton’s second law of motion?

Answer 7

When a net force acts on an object, the object will accelerate in the direction of the force, and the acceleration is directly proportional to the force and inversely proportional to the mass.

Question 8

What is Newton’s third law of motion?

Answer 8

When object A exerts a force on object B, object B simultaneously exerts an oppositely directed force of equal magnitude on object A.

Question 9

What is Newton’s Law of Universal Gravitation?

Answer 9

Each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Question 10

What is the difference between mass and weight?

Answer 10

Mass is a measure of the amount of matter in an object, while weight is the force exerted by gravity on that mass.

Question 11

What is momentum?

Answer 11

Momentum is the product of an object’s mass and its velocity.

Question 12

What is linear momentum?

Answer 12

Linear momentum is a vector quantity with the same direction as the velocity of the object.

Question 13

What is Newton’s second law of motion in terms of momentum?

Answer 13

The net (or resultant) force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force.

Question 14

What is meant by a system in Physics?

Answer 14

A system in Physics refers to a defined collection of objects being studied.

Question 15

What are internal and external forces in a system?

Answer 15

Internal forces are forces that objects within the system exert on each other, while external forces are forces exerted on the system from outside.

Question 16

What is an isolated system in Physics?

Answer 16

An isolated system is one where the net external force is zero, excluding external forces like friction.

Question 17

What is the principle of conservation of linear momentum?

Answer 17

The total linear momentum of an isolated system remains constant (is conserved).

Question 18

How is conservation of momentum applied to the collision of two objects?

Answer 18

Conservation of momentum can be applied to the collision of two objects moving in one dimension using an appropriate sign convention.

Question 19

What is a projectile?

Answer 19

A projectile is an object that has been given an initial velocity and then moves under the influence of gravitational force only.

Question 20

What is free fall?

Answer 20

Free fall is motion during which the only force acting on an object is the gravitational force.

Question 21

Define the work done on an object by a constant force F.

Answer 21

The work done is defined as F Δx cos θ, where F is the magnitude of the force, Δx is the magnitude of the displacement, and θ is the angle between the force and the displacement.

Question 22

State the work-energy theorem.

Answer 22

The work done on an object by a net force is equal to the change in the object’s kinetic energy. In symbols: Wnet = ΔK = Kf - K.

Question 23

Define a conservative force.

Answer 23

A conservative force is a force for which the work done in moving an object between two points is independent of the path taken.

Examples include gravitational force, elastic force in a spring, and electrostatic forces.

Question 24

Define a non-conservative force.

Answer 24

A non-conservative force is a force for which the work done in moving an object between two points depends on the path taken.

Examples include frictional force, air resistance, and tension in a chord.

Question 25

State the principle of conservation of mechanical energy.

Answer 25

The total mechanical energy in an isolated system remains constant, where the total mechanical energy is the sum of gravitational potential energy and kinetic energy.

Question 26

Define power.

Answer 26

Power is defined as the rate at which work is done or energy is expended.

Question 27

State the Doppler effect.

Answer 27

The Doppler effect is the change in frequency (or pitch) of the sound detected by a listener because the sound source and the listener have different velocities relative to the medium of sound propagation.

Question 28

Explain red shifts.

Answer 28

Red shifts refer to the phenomenon where light from an object moving away from an observer is shifted to longer wavelengths, indicating that the object is receding.

Question 29

State Coulomb's law.

Answer 29

Coulomb's law states that the magnitude of the electrostatic force exerted by one point charge (Q1) on another point charge (Q2) is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance (r) between them.

Question 30

Describe an electric field.

Answer 30

An electric field is a region of space in which an electric charge experiences a force. The direction of the electric field at a point is the direction a positive test charge would move if placed at that point.

Question 31

Define electric field at a point.

Answer 31

The electric field at a point is the electrostatic force experienced per unit positive charge placed at that point. In symbols: E = F/q.

Question 32

State Ohm's law in words.

Answer 32

The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature.

Question 33

Define emf.

Answer 33

Emf is defined as the maximum energy provided by a battery per unit charge passing through it.

Question 34

What is the energy conversion in generators?

Answer 34

Mechanical energy is converted into electrical energy.

Question 35

How does a generator work?

Answer 35

A generator works on the principle of electromagnetic induction.

Question 36

What are the functions of the components of an AC generator?

Answer 36

The components of an AC generator include the rotor, stator, and slip rings, which work together to produce alternating current.

Question 37

What are the functions of the components of a DC generator?

Answer 37

The components of a DC generator include the rotor, stator, and commutator, which work together to produce direct current.

Question 38

What are examples of the uses of AC generators?

Answer 38

AC generators are commonly used in power plants and for supplying electricity to homes.

Question 39

What are examples of the uses of DC generators?

Answer 39

DC generators are used in battery charging and in some types of electric vehicles.

Question 40

What is the energy conversion in motors?

Answer 40

Electrical energy is converted into mechanical energy.

Question 41

How does a motor work?

Answer 41

A motor works using the motor effect.

Question 42

What are the functions of the components of a motor?

Answer 42

The components of a motor include the rotor, stator, and power supply, which work together to convert electrical energy into mechanical motion.

Question 43

What are examples of the uses of motors?

Answer 43

Motors are used in appliances, vehicles, and industrial machinery.

Question 44

What is the energy conversion in generators?

Answer 44

Mechanical energy is converted into electrical energy.

Question 45

How does a generator work?

Answer 45

A generator works on the principle of electromagnetic induction.

Question 46

What are the functions of the components of an AC generator?

Answer 46

The components of an AC generator include the rotor, stator, and slip rings, which work together to produce alternating current.

Question 47

What are the functions of the components of a DC generator?

Answer 47

The components of a DC generator include the rotor, stator, and commutator, which work together to produce direct current.

Question 48

What are examples of the uses of AC generators?

Answer 48

AC generators are commonly used in power plants and for supplying electricity to homes.

Question 49

What are examples of the uses of DC generators?

Answer 49

DC generators are used in battery charging and in some types of electric vehicles.

Question 50

What is the energy conversion in motors?

Answer 50

Electrical energy is converted into mechanical energy.

Question 51

How does a motor work?

Answer 51

A motor works using the motor effect.

Question 52

What are the functions of the components of a motor?

Answer 52

The components of a motor include the rotor, stator, and power supply, which work together to convert electrical energy into mechanical motion.

Question 53

What are examples of the uses of motors?

Answer 53

Motors are used in appliances, vehicles, and industrial machinery.