Electricity Test

Question 1

What is the voltage unit ?

Answer 1

Volts

Question 2

What is a live (active) wire ?

Answer 2

Wire which carries electricity in it

Question 3

What is a neutral wire ?

Answer 3

Wire which completes the circuit back to the power source.

Question 4

What is the earth wire ?

Answer 4

Wire which connects the outer metal parts to the ground (earthing) to prevent electric shock.

Question 5

What appliances have 3 pin plugs and why ?

Answer 5

Electrical appliances with a metal case need to be earthed to prevent electric shock. They have 3 pin plugs.

Question 6

What appliances require 2 pin plugs and why ?

Answer 6

Appliances with an insulating case do not need the earth wire so they have 2 pin plugs.

Question 7

A 10amp fuse will ?

Answer 7

Allow a current of up to 10amps to flow through it before it melts.

Question 8

Circuit breakers are ?

Answer 8

Tripped when too much current flows through it. Circuit breakers do not need to be replaced.

Question 9

What is the voltage symbol ?

Answer 9

V

Question 10

What is the current symbol ?

Answer 10

I

Question 11

What is the resistance symbol?

Answer 11

R

Question 12

Electricity is a form of ?

Answer 12

Energy

Question 13

Electricity is sold in ?

Answer 13

Energy units called kilowatt. - hours (kWh)

Question 14

1kWh =

Answer 14

1000 Wh

Question 15

Different electrical appliances use ?

Answer 15

Different amounts of energy

Question 16

The rate at which an appliance uses energy is called ?

Answer 16

Its power

Question 17

What is power measured in ?

Answer 17

Watts. ( joules per second )

Question 18

How do you calculate kWh ?

Answer 18

Kilowatts multiplied by time divided by 1000 eg:

120 w x 12h
= 1440w.h divided by 1000
= 1.44

Question 19

Voltage =

Answer 19

Current times resistance

Question 20

Resistance =

Answer 20

Voltage divided by current

Question 21

Current =

Answer 21

Voltage divided by resistance

Question 22

What is the unit of current ?

Answer 22

Amps