6.2 Electricity

Question 1

Alternating Potential Difference

Answer 1

A continually oscillating current flow, which results in the potential difference across two points continually oscillating between
a positive and negative value

Question 2

Amperes (Amps)

Answer 2

The unit of current

Question 3

Attraction

Answer 3

A force pulling two opposite charges together, when they are brought near each other

Question 4

Coulomb

Answer 4

The unit of charge

Question 5

Diode

Answer 5

A component that only allows current to flow through in the forward direction.

They have very large resistances in the reverse direction

Question 6

Direct Potential Difference

Answer 6

A one-directional current flow

Question 8

Earth Wire

Answer 8

The green and yellow striped safety wire that prevents an appliance from becoming live

Question 9

Electrical Current

Answer 9

The rate of flow of electrical charge.

Its value is the same at any position in a single closed loop

Question 10

Electrical Work

Answer 10

When charge flows in a circuit, electrical work is said to be done

Question 11

Filament Lamp

Answer 11

A light emitting component consisting of an enclosed metal
filament.

Its resistance increases as the filament’s temperature increases

Question 12

Insulation

Answer 12

The coating around power cables that prevents electrocution and is colour coded to allow for easy identification

Question 13

Light Dependent Resistor (LDR)

Answer 13

A light sensitive component whose resistance increases as its temperature decreases

Question 14

Live Wire

Answer 14

The brown coloured wire that carries the alternating current from the supply in a mains power supply

Question 15

Mains Electricity

Answer 15

An a.c supply, which in the UK has a frequency of 50Hz a value of 230V

Question 16

Neutral Wire

Answer 16

The blue coloured wire that completes the circuit in a mains power supply

Question 17

Non-Contact Force

Answer 17

A force experienced between two separated objects

Examples include gravity, and magnetic and electric forces

Question 18

Ohmic Conductor

Answer 18

A conductor whose current flow is directly proportional to the
potential difference across it, when held at a constant temperature

Question 19

Ohms

Answer 19

The unit of resistance

Question 20

Parallel

Answer 20

Components connected in parallel have the same potential difference across each component.

The total current is equal to the sum of the currents flowing through each component

Question 21

Potential Difference

Answer 21

The product of a component’s resistance and the magnitude of current flow through it

Question 22

Repulsion

Answer 22

Caused when two like-charges are brought near each other

Question 24

Resistance

Answer 24

A measure of the opposition to current flow

Question 25

Resistors in Parallel

Answer 25

The total resistance is equal to the inverse of the sum of the inverses of the resistance of the parallel components The total resistance of two parallel resistors is always less than the lowest individual resistor value

Question 26

Resistors in Series

Answer 26

The total resistance is equal to the sum of the resistances of the individual components

Question 27

Series

Answer 27

Components connected in series have the same current passing through each component but share the total potential difference of the power supply

Question 28

Step-Down Transformers

Answer 28

Devices found between the transmission cables and the consumer that lower the potential difference of the power so it is at safe, usable levels

Question 29

Step-Up Transformers

Answer 29

Devices that increase the potential difference generated by a power station, so that the electrical power transmitted along the transmission cables is at a higher potential.

Question 30

The National Grid

Answer 30

The network of power stations, transformers and cables that connect consumers to power stations

Question 31

Thermistor

Answer 31

A temperature dependent component, whose resistance increases as its temperature decreases

Question 32

Volt

Answer 32

The unit of potential difference