B1 Domestic uses and safety

What colour is the insulation covering on a live wire?

• blue

• brown

• green and yellow

What do step-up transformers do in the National Grid?

• decrease the potential difference so its safe for the consumers

• increase the potential difference so that less energy is lost via heat

What is the equation linking power, current and potential difference?

• P= I x V

• P= I ÷ V

• P= V ÷ I

What is the frequency and potential difference of the domestic electricity supply in the UK?

• frequency of 230Hz and potential difference of 50V.

• frequency of 100Hz and potential difference of 200V

• frequency of 50Hz and potential difference of 230V

• frequency of 75Hz and potential difference of 250V.

What is the purpose of the National Grid?

• to generate electricity

• to increase the amount of electricity

• To link power stations to consumers