S4.7.2 Glossary

Question 1

Alternating current (AC)

Answer 1

Current which constantly changes direction

Question 2

Coulombs

Answer 2

Unit of measurement for charge

Question 3

Current

Answer 3

The rate of flow of charge

Question 4

Diode

Answer 4

Component which only allows current to flow in one direction

Question 5

Direct current (DC)

Answer 5

Current which only flows in one direction

Question 6

Earth wire

Answer 6

Wire which carries current if the appliance becomes live

Question 7

Light dependent resistor (LDR)

Answer 7

Component with low resistance in bright light

Question 8

Live wire

Answer 8

Wire which carries the current from the mains supply

Question 9

National Grid

Answer 9

Cables and transformers connecting power stations and homes

Question 10

Neutral wire

Answer 10

Wire which completes the circuit

Question 11

Ohmic conductor

Answer 11

A component which obeys Ohm’s law

Question 12

Parallel circuit

Answer 12

A circuit where different components are on different branches

Question 13

Potential difference

Answer 13

The difference in energy between two points of a circuit

Question 14

Power

Answer 14

The rate of energy transfer

Question 15

Resistance

Answer 15

The slowing down of current through a component

Question 16

Series circuit

Answer 16

A circuit with one complete loop

Question 17

Step-down transformer

Answer 17

Decreases potential difference and increases current

Question 18

Step-up transformer

Answer 18

Increases potential difference and decreases current

Question 19

Thermistor

Answer 19

Component with low resistance at high temperatures