Definitions

Question 0

Electromotive Force

Answer 0

Energy transferred per unit charge from chemical to electrical form.

Question 1

Resistance

Answer 1

Potential difference across a component/current in it.

Question 2

Kilowatt — Hour

Answer 2

(A unit of) energy equal to 3.6MJ or 1kW for an hour.

Question 3

The Ohm

Answer 3

A component with a resistance of 1(ohm) if a potential difference of 1V makes a current of 1A to flow through it.

Question 4

Potential Difference

Answer 4

Energy transferred per unit charge from electrical to other forms.

Question 5

Coulomb

Answer 5

Unit of charge. The amount of charge that passes in 1s when the current is 1A.

Question 6

Power

Answer 6

Work done/energy transferred per unit time.

Question 7

The Volt

Answer 7

1J per coulomb. The potential difference is 1V when 1J of energy is used to pass 1C of charge through a component.

Question 8

Resistivity

Answer 8

Resistivity = Resistance x Cross Sectional Area / Length

Question 9

Kirchoff’s First Law

Answer 9

The total current into a junction equals the total current out. Conservation of charge.

Question 10

Kirchoff’s Second Law

Answer 10

The sum of EMF’s = the total p.d around a (closed) loop (in a circuit). Energy is conserved.

Question 11

Displacement

Answer 11

The distance moved from equilibrium from a part on a wave.

Question 12

Amplitude

Answer 12

The maximum displacement (caused by wave motion).

Question 13

Wavelength

Answer 13

Distance between (neighbouring) identical points on a wave of the same phase.

Question 14

Period

Answer 14

Time taken for one complete oscillation.

Question 15

Phase Difference

Answer 15

Between two points on the same wave/waves of the same frequency, how far through the cycle one point is to another.

Question 16

Frequency

Answer 16

The number of wavelengths passing a point at a point per unit time or produced by the wave source.

Question 17

Speed of a Wave

Answer 17

Distance travelled by the wave (energy) per unit time.

Question 18

Nodes

Answer 18

A node occurs where the amplitude/displacement is (always) zero.

Question 19

Antinodes

Answer 19

An antibode occurs where the amplitude (of the standing wave) takes the maximum (possible) value.

Question 20

Fundamental Mode of Vibrations

Answer 20

The lowest natural frequency of a standing wave.

Question 21

Harmonics

Answer 21

Whole number multiples of the fundamental frequency of a stationary wave.

Question 22

Interference

Answer 22

When (two) waves meet (at a point) there is a change in overall intensity/displacement.