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1

What is a primary energy source?

Fuel that is used in the form in which it is found.

2

Name some primary energy sources?

Fossil fuels; nuclear fuel; biofuels

3

What are secondary energy sources?

Energy that has been converted from a primary source, eg electricity

4

Where does most of our energy come from?

Burning fossil fuels

5

What is the burning of fossil fuels doing to the atmosphere?

Increasing the CO2

6

Why is it a problem that we are increasing the amount of CO2 in the atmosphere?

The greenhouse effect is causing global warming

7

What is likely to happen as the result of global warming?

Climate change; floods and storms

8

What is power?

The amount of energy transferred in one second

9

What is power measured in?

Watt

10

What is a watt?

1 joule in 1 second

11

What is the equation for energy transfer?

Energy transferred (J) = Power (W) x Time (s)

12

What is domestic electricity measured in?

KWh (Kilowatt -hours)

13

What is a kilowatt-hour?

The energy transferred by 1kW in an hour

14

What is the flow of electricity called?

Current

15

What is current measured in?

Ampère (Amp)

16

What is the voltage of a power supply measured in?

Volts

17

How can the rate of power transfer to an electrical device be measured?

Power (W) = current (A) x voltage (V)

18

What is the power of an electrical device?

The rate at which it transfers energy from the power supply. This is often called the rating.

19

What energy transfers occur when a current flows in a circuit?

Energy in the component transfers the energy into other useful forms; energy in the wires is converted into heat

20

How would you draw a diagram to show energy transfers?

Sankey diagram. The thickness of each arrow tail is proportional to the energy. Wasteful energy always flows down, useful energy to the right.

21

What is the efficiency of an electrical component?

Efficiency = energy usefully transferred/ total energy supplied

22

What can the values for efficiency be?

Between 1 and 0. Greater than 1 means you are creating energy.

23

How can you use less energy?

Use high efficiency A rated components; turning off components when they are not needed; not boiling more water than needed; cooking in the microwave.

24

What can the nation do to use less energy?

Use more efficient cars; live in houses with better insulation; building more efficient power stations.

25

What will happen to global demand for energy?

It will rise due to population increases and increasing standard of living.

26

Which human activities have no impact on the environment?

They all do.

27

How can we reduce human impact on the environment?

recycling resources such as plastic, glass, paper; generating electricity from renewable sources of energy, eg water, wind, solar power.

28

What happens when you move a magnet near a circuit?

Current flows.

29

When does the flow of current induced by a magnet stop?

When the magnet stops moving.

30

How does a generator work?

A magnet is spun near a coil of wire.