physics: electricity

What is damaged insulation?

Contact with wire due to gaps i the insulation, causing electrical shocks

Explain overheating of cables

When high currents are passing through the wire, causing the wire to heat up, burning the insulation and catching fire

What is damp conditions?

Since water can conduct a current, wet electrical appliances can cause electric shocks

What is a fuse?

A thin piece of wire which overheats and melts if the current is too high

What is the purpose of a fuse?

Protecting the circuit

What should the current rating of a fuse be?

A little bit higher than the current used by the device in the circuit

What are the most common fuse current ratings

3A, 5A, 13A

What is a circuit breaker

It consists of an automatic electromagnet switch which breaks the circuit if the current rises over a certain value.

How does a circuit breaker compare to a fuse?

It is better and more efficient as it can be reset and used again

What is the function of earth wires

Creating a safe route for current to flow through in a short circuit

How do earth wires work

Having a low resistance, a strong current surges through them which breaks the fuse and disconnects the appliance

What is double insulation

Appliances with double insulation have either plastic casing or have been designed so the earth wire cannot touch the metal casing