Tier 2

Question 1

Principle of Conservation of Linear Momentum

Answer 1

The total linear momentum of an isolated system of interacting bodies before and after collision remains constant if no net external force acts on the system.

Question 2

Photon

Answer 2

A discrete packet of energy of electromagnetic radiation.

Question 3

Newton’s First Law of Motion

Answer 3

An object stays at rest or continues to move at constant velocity unless a resultant force acts on it.

Question 4

Newton’s Second Law of Motion

Answer 4

Rate of change of momentum of a body is directly proportional to the resultant force acting on it and takes place in the direction of the resultant force.

Question 4

Newton’s Third Law of Motion

Answer 4

When body A exerts a force on body B, body B exerts on body A a force of the same type, equal in magnitude but opposite in direction.

Question 5

Internal energy of an ideal gas

Answer 5

The sum of the kinetic energy due to random motions by a distribution of particles and potential energy due to intermolecular forces between the particles. In an ideal gas, there is no intermolecular forces between particles, hence potential energy equals to zero and internal energy equals to kinetic energy only.

Question 5

Electromotive force

Answer 5

The energy transformed from chemical to electrical per unit charge when a charge is driven round a circuit.

Question 5

Simple harmonic motion

Answer 5

A type of oscillatory motion where the acceleration is directly proportional to displacement from the equilibrium position and directed opposite to displacement.

Question 6

Newton’s Law of Gravitation

Answer 6

Gravitational force of attraction between two point masses is directly proportional to the product of the masses and inversely proportional to the square of separation between the masses.

Question 6

Nuclear Fission

Answer 6

Splitting of a single heavy nucleus when bombarded by neutrons to form two or more light nuclei of approximately same mass with neutrons emitted.

Question 7

Nuclear Fusion

Answer 7

Combining of two or more light nuclei under very high temperatures to form, more massive nucleus.

Question 8

Half life

Answer 8

Time taken for the number of undecayed nuclei to be reduced to half of its original number.

Question 8

Spontaneous process

Answer 8

Probability of decay is unaffected by external factors such as temperature, pressure or chemical composition.

Question 9

Random process

Answer 9

Impossible to predict if an unstable nucleus will decay at any point in time, only probability of decay after a period of time is known.

Question 9

Binding energy

Answer 9

The minimum energy required to separate the nucleons in a nucleus to infinity.

Question 9

Threshold frequency

Answer 9

The minimum frequency of electromagnetic radiation to cause emission of electron from the surface of a metal.

Question 9

Rayleigh Criterion

Answer 9

The limit for which 2 sources of light can be just distinguished is when the first minimum of the diffraction pattern of one source coincides with the central maximum if the diffraction pattern of the other source.

Question 10

Polarized wave

Answer 10

In polarised waves, the oscillations are along one direction only, in a single plane that is normal to the direction of energy transfer of the wave.

Question 11

Transverse wave

Answer 11

Wave where the oscillations are normal to the direction of energy propagation.

Question 12

Condition of equilibrium

Answer 12

There is no resultant force acting on the body and there is no resultant torque about any point.

Question 13

Field of force

Answer 13

A region of space where a particle experiences a force.

Question 14

Vector

Answer 14

A physical quantity that has both magnitude and direction.

Question 15

Principle of moments

Answer 15

In rotational equilibrium, the sum of clockwise moment about any point is equal to the sum of anti-clockwise moment about the same point

Question 16

Hooke’s Law

Answer 16

The change in length of a material is directly proportional to the force applied on it, provided that the limit of proportionality is not exceeded.

Question 17

Inelastic collisions

Answer 17

Total kinetic energy of system of bodies after collision is less than before.