All definitions

Question 1

Accuracy

Answer 1

How close a measured value or average of repeated measured values is to the true value

Question 2

Precision

Answer 2

How close the repeated measured values are to each other, without regard to true value

Question 3

Electric current

Answer 3

The rate of flow of charge

Question 4

Electromotive force

Answer 4

The energy transferred from non-electrical forms to electrical forms, per unit charge in driving a unit charge around a complete circuit

Question 5

Potential difference

Answer 5

The energy transferred, from electrical to non-electrical forms, per unit charge when a unit charge passes from one point to another

Question 6

Power

Answer 6

Rate of energy transfer

Question 7

Period in a.c.

Answer 7

Time taken for an alternating current to repeat itself

Question 8

Frequency in a.c.

Answer 8

Number of repetitions of the alternating current per unit time

Question 9

Peak value in a.c.

Answer 9

Maximum value of the alternating current

Question 10

Root mean-square of a.c. or voltage

Answer 10

Value of steady direct current (or voltage) that dissipates heat energy in resistor at same average rate as that is dissipated by alternating current (or voltage)

Question 11

Force

Answer 11

The rate of change of momentum of an object which is free to move. Direction of force is direction of change in momentum

Question 12

Conservative force

Answer 12

Force is conservative if work it does on an object moving between two points is independent of the path the object takes

Question 13

Non conservative force

Answer 13

Force is non-conservative if work it does on an object depends on the path taken by object between initial and final points

Question 14

Frictional force

Answer 14

The force exerted by one body on another body when two bodies slide over one another. It is caused by irregularities in surfaces in mutual contact and depends on surfaces in contact as well as how much they are pressed against each other. It is component of contact force along surface of contact

Question 15

Viscous force

Answer 15

Frictional force experiences either by an object as it moves through a fluid or by a fluid as it moves over a surface

Question 16

Centre of gravity

Answer 16

The single point at which the entire weight of body can be considered to act

Question 17

Hooke’s Law

Answer 17

The force is directly proportional to extension, provided that the elastic limit has not been exceeded

Question 18

Moment of force

Answer 18

Product of magnitude of the force and perpendicular distance of force from that point

Question 19

Torque of couple

Answer 19

Product of one of the forces and perpendicular distance between the forces

Question 20

Couple

Answer 20

Consists of a pair of forces of equal magnitude but acting in opposite direction whose lines of actions are parallel but separate

Question 21

Translational equilibrium

Answer 21

When resultant force on body is zero in any direction, no acceleration of centre of mass and body is said to be in translational equilibrium

Question 22

Rotational equilibrium

Answer 22

Resultant torque of a body is zero about any axis of rotation, there is no angular acceleration of the object and body is said to be in rotational equilibrium

Question 23

Principle of Moments

Answer 23

When a system is in equilibrium, sum of clockwise moments about any axis is equal to sum of anticlockwise moments about same axis

Question 24

Field of force

Answer 24

Region of space where force is felt

Question 25

Elastic limit

Answer 25

Point beyond which the spring does not return to its original length when load is removed

Question 26

Pressure

Answer 26

Force per unit area

Question 27

Hydrostatic pressure

Answer 27

Pressure at certain depth or at point in liquid

Question 28

Tensile forces

Answer 28

Two forces acting in opposite directions on an object so as to tend to increase its length along direction of forces

Question 29

Compressive forces

Answer 29

Two forces acting in opposite directions on an object so as to tend to reduce its length along direction of forces

Question 30

Centre of mass

Answer 30

The mean location of all mass in the system. It is the point through which a single force must act for the object to accelerate linearly without any rotation

Question 31

Terminal velocity

Answer 31

The constant velocity achieved by an object when it is falling under gravity through a viscous fluid

Question 32

Work done

Answer 32

The product of the force and the displacement of the body in the direction of the force

Question 33

Force field

Answer 33

A region of space in which a body experiences a force without physical contact with another body. Force field is produced by presence of another body

Question 34

Gravitational field strength

Answer 34

The gravitational force per unit mass on a mass placed at that point

Question 35

Electric field strength

Answer 35

The electric force per unit positive charge (acting on a small stationary charge) placed at that point

Question 36

Power

Answer 36

Rate of energy transfer