Domestic Electricity

Question 1

What do AC and DC stand for?

Answer 1

Alternating Current and Direct Current.

Question 2

What kind of electric current does a battery use?

Answer 2

Direct Current.

Question 3

What kind of current is in use in scenarios of constant electronic supply?

Answer 3

Alternating Current.

Question 4

How does direct current work?

Answer 4

Direct Current maintains a constant voltage: electrons move in a single direction.

Question 5

How does alternating current work?

Answer 5

The current constantly changes direction: how often this happens is the measure of frequency.

Question 6

What is the unit of frequency?

Answer 6

Hertz (Hz).

Question 7

At 50 Hz, how often does the direction of electrons change?

Answer 7

50 times per second.

Question 8

What is the charge of British Mains power?

Answer 8

230V.

Question 9

What is amplitude the measure of?

Answer 9

The peak of a wave.

Question 10

What is the measure of the length of a wave?

Answer 10

Wavelength.

Question 11

How do you determine the frequency of a current?

Answer 11

Divide one by the time for one cycle.

Question 12

What does a blue wire represent?

Answer 12

The neutral wire.

Question 13

What does the striped yellow and green wire represent?

Answer 13

The earth wire.

Question 14

What does the brown wire represent?

Answer 14

The live wire.

Question 15

Which feature of a plug maintains the position of the wire?

Answer 15

The cable grip.

Question 16

Which wire is the fuse attached to?

Answer 16

The live wire.

Question 17

What is the job of the live wire?

Answer 17

To carry the current into the appliance.

Question 18

Which wire carries the current into the appliance?

Answer 18

The live wire.

Question 19

Which wire completes the circuit and carries the current out of the appliance?

Answer 19

The neutral wire.

Question 20

What is the job of the neutral wire?

Answer 20

To complete the circuit and carry the current out of the appliance.

Question 21

When is an earth wire necessary?

Answer 21

When the plug case is not plastic.

Question 22

What happens if the live wire touches a metal case?

Answer 22

There’s a short circuit.

Question 23

What is the job of the earth wire?

Answer 23

To remove the current if the live wire causes a short circuit.

Question 24

What are fuses?

Answer 24

A safety device designed to prevent fires.

Question 25

How do fuses work?

Answer 25

By melting at the point the current becomes too high. THis breaks the circuit.

Question 26

What is the safety device included in plugs designed to prevent fires?

Answer 26

The fuse.

Question 27

What measure should be taken when a fuse breaks?

Answer 27

It must be replaced.

Question 28

What are circuit breakers?

Answer 28

A safety device that uses an electromagnet to flick the switch if the current becomes too high.

Question 29

What is the scientific term used to describe circuit breakers?

Answer 29

MCB (miniature circuit breaker).

Question 30

Define electromagnetic.

Answer 30

Relating to the interrelation of electric currents or fields and magnetic fields.

Question 31

What are the advantages of MCBs?

Answer 31

They can be reset, and they are faster to detect and react to voltages.

Question 32

What is a Residual Current Circuit Breaker?

Answer 32

A device that measures and monitors the current within neutral wires: if there is a difference, it breaks the circuit.

Question 33

Which safety device monitors and measures the current in neutral wires, switching off circuits in circumstances of imbalance?

Answer 33

A Residual Current Circuit Breaker (RCCB).

Question 34

What are the advantages of RCCBs?

Answer 34

They are more sensitive than MCBs, and prevent electric shocks.