Unit 1

Question 1

Newton’s second law

Answer 1

Acceleration of an object is directly proportional to the magnitude of the force and inversely proportional to the mass of the object

Question 2

Newton’s third law

Answer 2

For every action, there is an equal and opposite reaction

Question 3

Principle of moments

Answer 3

The total clockwise moments equals the total anti-clockwise moments (about the same point) when in equilibrium

Question 4

Moment of force about a point

Answer 4

The product of force and the perpendicular distance (from point to the line of action of the force)

Question 5

Resistivity

Answer 5

The resistance of 1 m of material of cross sectional area 1 m^2

Question 6

Vector

Answer 6

A vector quantity has a magnitude unit and DIRECTION

Question 7

Scalar

Answer 7

A scalar quantity has a magnitude and unit and NO direction

Question 8

Conservation of energy

Answer 8

Energy cannot be created or destroyed but it can change from one form to another

Question 9

Hooke’s law

Answer 9

Extension is directly proportional to applied load provided the limit of proportionality is not exceeded

Question 10

Potential difference

Answer 10

Energy generated for every coulomb passing between them

Question 11

Ohm’s law

Answer 11

Potential difference across a conductor is proportional to current through it

Question 12

Projectile motion

Answer 12

(Uniformly) accelerated motion in one direction, constant speed in the perpendicular direction

Question 13

Power

Answer 13

Power is the rate of doing work

Question 14

Efficiency

Answer 14

Efficiency is the fraction on input energy that does work

Question 15

Strain

Answer 15

Ratio of extension to (unstretched) length

Question 16

Base units

Answer 16

A unit which all other units are derived. 
Kg- kilogram
m-meter
s-second
A-ampere
Mol-Mole
K-kelvin

Question 17

Electromotive force

Answer 17

Energy converted from other forms to electrical energy when unit charge passes through it

Question 18

Work

Answer 18

The product of force and distance moved in the direction of the force

Question 19

Current

Answer 19

The rate of flow of charge

Question 20

The volt

Answer 20

One joule of energy is dissipated per coulomb of charge

Question 21

Derived unit

Answer 21

Unit made up from a combination of two or more base units

Question 22

Ultimate tensile stress

Answer 22

Maximum stretching for per unit area without breaking

Question 23

Young’s modulus

Answer 23

The ratio of the stress of a material to the strain of the material

Question 24

Newton’s first law

Answer 24

An object will remain at rest or in uniform motion in a straight line unless acted upon by an external force

Question 25

Ohmic and non ohmic behaviour

Answer 25

Ohmic behaviour means Potential difference across a conductor is proportional to current through it
Non ohmic means the PD is inversely proportional

Question 26

Electrical power

Answer 26

The rate at which electrical energy is converted into other forms by a circuit or component