Safety with Electricity

Question 1

What is a short circuit

Answer 1

A path of low resistance for current

Question 2

What is a fuse

Answer 2

An electrical component with a low melting point

High resistance conductor

Question 3

What is a melting point

Answer 3

The temperature at which a substance melts

Question 4

Why is lighting usually connected in parallel

Answer 4

If one bulb fuses the rest of the lights remain on
If one appliance is faulty or switched off, you can still use the other appliances
The current does not diminish if more appliances are switched on at the same time

Question 5

What are the 3 safety devices

Answer 5

Circuit breakers
Fuse
3-Pin Plug

Question 6

What is a circuit breaker

Answer 6

When there is an overload or short circuit, it brings excess current
A circuit breaker is an electromagnetic switch designed to break the circuit when current gets too high
Too much current makes the magnetic field strong enough to open the switch

Question 7

What is a fuse

Answer 7

A fuse is a component that has a low melting point

Question 8

How does a fuse work

Answer 8

When a circuit is overloaded, excess current is generated and this brings excess heat. Since the fuse has a low melting point it will overheat and melt and thus break the circuit

Question 9

What are the 3 wires in a 3-Pin plug and what are their respective colours

Answer 9

Live Wire (Brown)
Neutral wire (Blue)
Earth wire (Yellow or green)

Question 10

What is the purpose of a live wire

Answer 10

Carries a voltage that alternates between a negative and positive voltage

Question 11

What is the purpose of a neutral wire

Answer 11

Completes the circuit. It is kept at a zero voltage

Question 12

What is the purpose of the earth wire

Answer 12

Connected to the metal casing of an appliance

The earth wire is connected via the wall plug to and earth cable that goes into the ground

Question 13

How does the earth wire work

Answer 13

If the metal casing becomes charged due to a fault, the charge is safely discharged to the ground via the earth cable

Question 14

What safety features must you follow when wiring a plug

Answer 14

Ensure the wires are connected to the correct terminals
Make sure there are no loose or bare wires
Ensure the cable grip is firmly secured to hold the cable in place
Some plugs can have a fuse fitted of the correct value