Mains Electricity

Question 0

Double insulated appliances

Answer 0

Have cases that do not conduct (usually plastic) and have no metal parts that you can touch, so they do not need an earth wire

Question 1

Purpose of cable grip

Answer 1

Stop the wires being pulled out

Question 2

If a device works at 3A what fuse should be used

Answer 2

5A

Question 6

What does a.c. stand for?

Answer 6

Alternating current (direction of current changes)

Question 7

How does a 13A fuse differ from a 3A fuse?

Answer 7

The wire is thicker, allowing more current to flow through

Question 8

Why are kWh used to record electrical energy in a household instead of joules

Answer 8

Joules would be an inappropriate unit of measurement when recording electrical energy in a household as the figures would be too large to use in calculations

Question 9

Why are there two colours on the earth wire?

Answer 9

For the benefit of people who are colour blind

Question 10

When does an RCB break the circuit

Answer 10

When it detects a difference between live and neutral wires