Generating electricity test questions - WJEC

1

Which of the following is a renewable energy source?

2

What does the carbon dioxide released when fossil fuels are burnt contribute to?

3

Which of the following is an unreliable source of energy?

4

What type of energy does coal store?

5

What is the % efficiency of this filament lamp?

Sankey diagram for a filament lamp. It is labelled Electrical energy 200 Joules, Light energy 40 Joules and Heat energy 160 Joules.

6

What does this diagram show?

The main features of the National Grid - a power station, step-up transformers, high voltage transmission lines, step-down transformers and a home. They are labelled 1, 2, 3, 4 and 5 respectively.

7

What does a step-up transformer do?

8

What types of power stations provide the base load of electricity in the National Grid?

9

A power station produces 3 GW of power at a voltage of 50,000 V. What is the current that is produced?

10

A transformer has an input power of 3.5 × 109 W. What is the useful output power if the transformer is 90% efficient?