Definition

Question 1

Define Scalar Quantity

Answer 1

Physical quantities that have magnitude only

Question 2

Define Vector quantity

Answer 2

Physical quantities that have both magnitude and direction

Question 3

Define Speed

Answer 3

Rate of change of distance

Question 4

Define Velocity

Answer 4

Rate of change of displacement

Question 5

Define acceleration

Answer 5

Rate of change of velocity

Question 6

Define Uniform Acceleration

Answer 6

Constant Rate of Change of Velocity

Question 7

Define Inertia

Answer 7

The mass of a body resists a change in the state of rest or motion of the body

Question 8

Define Mass

Answer 8

The amount of substance in a body

Question 9

Define Weight

Answer 9

Force of gravity acting on a body

Question 10

Define Density

Answer 10

Mass per unit volume

Question 11

Define Gravitational Field

Answer 11

A region in which a mass experiences a force due to gravitational attraction

Question 12

Define Gravitational Field Strength

Answer 12

Gravitation Force per unit mass

Question 13

Define Principle of moments

Answer 13

When a body is in equilibrium, the sum of clockwise moment about any pivot is equal to the sum of anti-clockwise moment about the same pivot

Question 14

Define Centre of Gravity

Answer 14

Point about which the weight of the body seems to act

Question 15

Define Pressure

Answer 15

Force acting per unit area

Question 16

Define Principle of conservation of energy

Answer 16

Energy cannot be created nor destroyed, but can be converted from one form to another. Total energy in an isolated system is constant

Question 17

Define Energy

Answer 17

Capacity to do work

Question 18

Define Work Done

Answer 18

Product of Force and distance moved in the direction of the `force

Question 19

Define Power

Answer 19

Rate of doing work or energy conversion

Question 20

Define Conduction

Answer 20

The transfer of thermal energy through a medium without any flow of the medium

Question 21

Define Convection

Answer 21

The transfer of thermal energy by means of convection current in a fluid (liquid or gas), due to a difference in density

Question 22

Define Radiation

Answer 22

The transfer of thermal energy in the form of electromagnetic waves such as infrared radiation, without the aid of a medium

Question 23

Define Wave speed

Answer 23

Distance moved by a wave in a second

Question 24

Define Frequency

Answer 24

Number of completed waves produced per second

Question 25

Define Wavelength

Answer 25

Distance between any two identical point on successive waves

Question 26

Define Period

Answer 26

Time taken to produce one complete wave

Question 27

Define amplitude

Answer 27

The maximum possible displacement of a point from its rest position

Question 28

Define Wavefront

Answer 28

Line that joins all identical points on a wave

Question 29

Define transverse wave

Answer 29

Wave that travels in a direction perpendicular to the direction of vibrations

Question 30

Define longitudinal wave

Answer 30

Wave that travels in a direction parallel to the direction of vibration

Question 31

Define Ultrasound

Answer 31

Sound with frequency exceeding the upper limit of human hearing of 20000Hz

Question 32

Define current

Answer 32

Rate of flow of charge

Question 33

Define Electromotive Force

Answer 33

Work Done by a source in driving a unit charge around a complete circuit

Question 34

Define Potential Difference

Answer 34

Work Done to drive a unit charge through the component

Question 35

Define Resistance

Answer 35

The ratio of the potential difference across a component to the current flowing through the component

Question 36

Define Fuse

Answer 36

Prevent excessive current flow due to faults like short circuit, by melting and becomes an open circuit. Prevent fire and equipment damaged

Question 37

Define fuse rating

Answer 37

The maximum allowable current to flow through a fuse before it blows

Question 38

Define Circuit Breaker

Answer 38

Trip and switch off the electrical supply in a circuit when there is an excessive flow of current. Prevents fire and equipment damaged

Question 39

Define live wire

Answer 39

- Live Wire is colour-coded brown - Deliver electrical energy to the appliance, connected to a high potential (240V)

Question 40

Define Neutral Wire

Answer 40

- Neutral Wire is colour-coded blue - Completes the circuit by forming a path for current to flow back to the supply, connected to zero potential (0V)

Question 41

Define Earth Wire

Answer 41

- Earth Wire is colour-coded green and yellow - Is a safety device by allowing unusually large current to flow through it, instead of the user. Usually zero current. Prevents electric shocks.