Practice Questions

1. Define the term national grid

National Grid is a network of transformers and cables that will distribute electricity from power stations to consumers such as homeowners, factories and offices. 

2. Why is the electricity transmitted as a high potential difference, low current?

Electricity transmission is more efficient if a large potential difference is used, because it means a smaller current will flow. The smaller the current, the smaller the power loss due to resistance heating in the electrical cables.

3. State the role of transformers in the transmission of electricity.

Transformers will increase an alternating potential difference and can decrease an alternating potential difference.