Mains electricity

Question 1

What is renewable energy?

Answer 1

Energy which can be replenished, naturally occuring energy.

Question 2

What is non renewable energy?

Answer 2

Energy which when produced the substance is used up and cannot be re-obtained.

Question 3

What are the three fossil fuels?

Answer 3

Coal, oil and natural gas.

They release heat energy when burned.

Question 4

How does a fossil fuel power station work?

Answer 4

• A fossil fuel (eg coal) is burned and heat energy is released
• This heat energy is used to boil water creating steam
• This steam rises up and along to turbines where the turbines are turned by the movement of the steam
• This turbine powers a generator, creating electricity

Question 5

What do fossil fuels release?

Answer 5

Carbon dioxide which contributes to the greenhouse effect.

Question 6

What is carbon capture?

Answer 6

A technology which involves separating carbon dioxide from waste gases, then storing it underground.
Prevents CO2 building up in the atmosphere

Question 7

What are the main nuclear fuels?

Answer 7

Uranium and plutonium.

Question 8

How is energy obtained from nuclear fuels?

Answer 8

Nuclear fission reactions ( where the nuclei in atoms are split ) occurs to release heat energy.

Question 9

What happens after nuclear fission to generate electricity?

Answer 9

In the same way as fossil fuels, used to heat water making steam, which turns turbines which powers a generator generating electricity.

Question 10

Advantages and disadvantages of using nuclear fuels:

Answer 10

Advantages:
-Unlike fossil fuels, do not produce carbon dioxide or sulphur dioxide

Disadvantages:

• An accident can result in large amounts of radioactive material getting released into the environment
• Needs to be stored as nuclear waste remains radioactive and harmful for thousands of years.

Question 11

Advantages and disadvantages of wind energy:

Answer 11

Advantages:
-Produces no harmful pollutants

Disadvantages:

• Can be noisy
• May spoil the view for nearby people
• Unreliable, no wind means no wind energy is produced

Question 12

Waves, tidal and hydroelectric:

Answer 12

Utilise the movement of water to generate electricity.
Advantages:
-No pollutants
-No fuel costs
Disadvantages:
-Can destroy habitats
-Increase in flooding
-Vegetation goes underwater if flooded, releasing methane

Question 13

What happens in a geothermal power station?

Answer 13

Radioactive elements in rocks underground such as uranium heat up cold water that is pumped down underground

• This water is heated by the radioactive decay in the element in the rock which returns the water to the surface as steam
• The steam turns a turbine, powering a generator, producing electricity

Question 14

Advantages and disadvantages of geothermal power:

Answer 14

Advantages:
-Produces no pollutants
-Renewable
-No fuel costs
Disadvantages:
-Not many suitable places in the world

Question 15

Difference between solar cells and solar panels:

Answer 15

Solar cells: turn light energy directly into electrical energy
Solar panels: use heat energy from the sun to heat up water

Question 16

Advantages and disadvantages of solar energy:

Answer 16

Advantages:
-Renewable
-Can provide electricity in remote locations
-No harmful gases produced
Disadvantages:
-Expensive and inefficient
-Solar cells don't work at night

Question 17

What is the startup times from shortest to longest for power stations?

Answer 17

• Gas fired station (shortest)
• Oil
• Coal
• Nuclear power station

Question 18

What is the purpose of the national grid?

Answer 18

To distribute electricity from power stations to consumers.

Question 19

How does the amount of current effect heat loss in wires?

Answer 19

The higher the current, the more the heat is lost.

Question 20

How does the national grid transmit electricity?

Answer 20

With a low current for minimum heat loss, which requires a high voltage.

Question 21

What do transformers do?

Answer 21

A device which changes the voltages of an alternating current supply.

Question 22

What does a step up transformer do?

Answer 22

Increases the voltage.

Question 23

What does a step down transformer do?

Answer 23

Lower the voltage.

Question 24

What is the order in which electricity travels from the power station?

Answer 24

• step up transformers
• high voltage transmission lines
• step down transformers
• consumers