Transformers and the National Grid

Question 1

Where are transformers found?

Answer 1

• In the national grid
• In the adaptors for certain electrical appliances like laptops and mobile phones

Question 2

What is the national grid?

Answer 2

A system of cables and transformers linking the power stations to consumers.

Question 3

Explain why the p.d. is stepped up before it is transferred via National Grid. (4)

Answer 3

• The current is reduced at a step-up transformer.
• A current causes a heating effect
• Since less current flows, the heating effect is less.
• This makes the transfer of energy more efficient and less costly to the company and consumer.

Question 4

Explain why step-down transformers are needed.

Answer 4

• Step-down transformers decrease the p.d. and increase the current.
• Making the electricity safer for the user.

Question 5

Explain the advantage of transmitting electrical power through