P5-electricity In The Home

Question 1

In the uk alternating current has a fréquency of what?

Answer 1

50 hertz Hz

Question 2

In the uk alternating current has a potential difference of around?

Answer 2

230 volts

Question 3

What is the live wire and what is it connected to?

Answer 3

Brown wire
Carries the alternating potential difference from the supply (230 volts)
The live wire is connected to a fuse in the plug

Question 4

What is the neutral wire?

Answer 4

The blue wire. Complete the circuit. Potential difference = 0V compared to the live wire

Question 5

What is the earth wire?

Answer 5

Green/ yellow striped wire. This is a safety wire to stop the appliance from becoming live.

Question 6

What is the national grid?

Answer 6

It is a system of transformers and cables.

Question 7

How do you measure the frequency of an a.c supply

Answer 7

Frequency = 1/ time taken for 1 cycle

Question 8

The peak potential difference of an a.c. supply is the

Answer 8

Maximum voltage measured from zero volts

Question 9

What is the equation for the energy transferred to a device

Answer 9

E = P x t

Energy transferred = power x time

Question 10

What is the equation for the electrical power supplied to an appliance

Answer 10

P = I x v

Power( watts) = current (amps A) x potential difference volts v

Question 11

What is the equation for p power supplied to the resistor

Answer 11

Power p = current^2 x resistance r

This equation can be used for choosing a fuse

3A 5A or 13A