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Question 1

1. What is the demand from energy doing?

Answer 1

-continually increasing

Question 2

1. What is happening as a result of the increasing demand for energy?

Answer 2

• issues about the availability of energy sources

- issues about the environmental effects of using these sources

Question 3

2. What are the main primary energy sources that humans use?

Answer 3

• fossil fuels (oil, gas, coal)
• nuclear fuels
• biofuels
• wind
• waves
• radiation from the Sun

Question 4

3. Why is electricity called a secondary energy source?

Answer 4

-because it is produced using another energy source (primary energy source)

Question 5

4. What do power stations which burn fossil fuels produce? What are the effects of this?

Answer 5

-power stations which burn fossil fuels produce carbon dioxide which contributes to global warming and climate change

Question 6

5. What happens when electric current passes through a component (or device)?

Answer 6

-energy is transferred from the power supply to the component and/or to the environment

Question 7

6. What is the power of an appliance?

Answer 7

• a measure of the amount of energy it transfers each second

- i.e. the rate at which it transfers energy

Question 8

6. What is the unit that power is measured in?

Answer 8

• watts (W)

- kilowatts (kW)

Question 9

7. What is the equation used to calculate the amount of energy transferred in a process, in joules and in kilowatt hours?

Answer 9

Energy transferred (joules, J, kilowatt hours, kWh )= power (watts, W, kilowatts, kW) × time (seconds, s, hours, h)

Question 10

7. What is energy transferred measured in?

Answer 10

• joules, J

- kilowatt hours, kWh

Question 11

8. What is the equation to calculate the rate at which an electrical device transfers energy?

Answer 11

Power (watts, W) = voltage (volts, V) × current (amperes, A)

Question 12

8. What is voltage measured in?

Answer 12

-volts, V

Question 13

8. What is current measured in?

Answer 13

• amperes, A

Question 14

9. What is a joule?

Answer 14

-a very small amount of energy

Question 15

9. What do domestic electricity meters measure the energy transfer in?

Answer 15

-kilowatt hours

Question 16

13. What is the equation to find efficiency in the context of electrical appliances and power stations?

Answer 16

Efficiency = (power [or energy] usefully transferred / total power supplied) × 100%

Question 17

14. How can we reduce energy usage in personal contexts?

Answer 17

• reduce energy initially used

- reduce energy lost

Question 18

14. What are examples of ways to reduce energy usage through reducing energy lost in personal contexts?

Answer 18

• loft insulation
• double glazing
• Thick curtains

Question 19

14. What are examples of ways to reduce energy usage through reducing energy initially used in personal contexts?

Answer 19

• energy saving light bulbs
• switching things off
• washing clothes at lower temperatures
• turning heating down

Question 20

14. What are examples of ways to reduce energy usage in national contexts?

Answer 20

• investing in alternate energy sources
• improving recycling services
• making laws to ensure buildings are energy efficient

Question 21

14. What are examples of ways to reduce energy usage in workplace contexts?

Answer 21

-computers should be switched off when not in use
-not printing and photocopying unnecessarily
-better transport to work
(public transport, car sharing)