Mains electricity

Question 1

What happens to a fuse if the current in a circuit is too large?

Answer 1

The fuse wire becomes hot and melts. The fuse “blows”. The circuit is now incomplete and there is no current preventing you from getting a shock and reducing the possibility of an electrical fire.

Question 2

What does the earth wire do?

Answer 2

It connects to an appliance’s metal casing so the if the live wire becomes damaged or breaks and comes into contact with the casing, the earth wire provides a low-resistance path for the current. This current is likely to be large enough to blow the fuse and turn the circuit off. Without the earth wire anyone touching faulty appliances would receive a severe shock as the current passed through them to the earth.

Question 3

What is double insulation?

Answer 3

All the electrical parts of an appliance are insulated so that they cannot be touched by the user.

Question 4

Where is the heating effect of electricity used?

Answer 4

Kettles, toasters, dishwashers, electric cookers, electric fires, light bulbs, hair dryers and washing machines

Question 5

What does current in a resistor result in?

Answer 5

The electrical transfer of energy and an increase in temperature

Question 6

Is mains electricity AC or DC?

Answer 6

Alternating current

Question 7

What can lamps and LEDs do?

Answer 7

Indicate the presence of current in a circuit