Electricity

Question 1

What is the national grid ?

Answer 1

The National Grid is used to distribute electricity around the country from power stations to consumers. It is the network of pylons and wires you see high above you across the country.

Question 2

A step-up transformer steps the voltage up and the current …

Answer 2

…decreases

Question 3

Explain why transformers are used in the national grid

Answer 3

Transformers allow the power to stay high because a high voltage means the current can be lowered. This stops the wire getting warm and losing energy to the surroundings.

Question 4

What is ac / dc

Answer 4

Ac=alternate current

Dc=direct current

Question 5

What is the voltage and frequency of the main ?

Answer 5

In the UK, the frequency of mains electricity is 50 Hertz. The voltage of mains electricity supplied to UK homes is 230 V.

Question 6

What is the main and pd of the blue wire ?

Answer 6

The neutral wire 0V

Question 7

How do you calculate power?

Answer 7

Power=currentxvoltage

Question 8

What is the rule for voltage in series circuit ?

Answer 8

The voltage from a battery is shared between all the components in a series circuit.

Question 9

What is the rule for the current in a series circuit ?

Answer 9

The current only has one route through the circuit . Therefore all the ammeters should read the same current