Domestic Uses and Safety

Cards (13)

Is mains supply a.c or d.c supply? What do each of these stand for?
Mains supply is an a.c supply.
(Alternating current)
Define alternating and define direct current.
Alternating Current: Current that continously changes direction at a specific frequency.
Direct Current: One directional current flow.
What is Frequency of the UK mains electricity supply?
50 Hz
What is the voltage of the UK mains electricity supply?
230V
Name three wires connecting electrical appliances to the mains?
Live wire
Neutral wire
Earth wire
State the insulation colour of the Earth wire?
Green/yellow
State the insulation colour of the live wire?
Brown
State the insulation colour of the neutral wire?
Blue
Explain when the Earth wire does not carry any current.
Under normal circumstances no current flows through the earth wire
If a fault occurs in the appliance (such as a surge or the casing becomes live), current will flow to the ground.
What potential is the neutral wire at?
0 volts.
State the potential difference between live and earth wires.
230 volts
What is the purpose of the neutral wire?
To complete the circuit by connecting the appliance to mains supply
For metal appliances where is the Earth wire connected to and why?
The casing of the appliance, if the live wire becomes loose and touches casing the current will flow through the earth wire, preventing electrocution