Energy Transfers - Paper 1

Question 1

When is work done in a circuit?

Answer 1

When charge is flowing.

Question 2

Define National Grid

Answer 2

The National Grid is a system of cables and transformers linking power stations to consumers.

Question 3

How are transformers used in the National Grid?

Answer 3

Step-up transformers are used to increase the potential difference from the power station to the transmission cables then step-down transformers are used to decrease, to a much lower value, the potential difference for domestic use.

Question 4

Why is the National Grid system an efficient method of energy transfer?

Answer 4

Massive potential difference reduces current, which reduces energy dissipated by wires and increases the efficiency of energy transfer.