P3

Question 1

What is a biofuel?

Answer 1

A fuel obtained from a living (or a recently living) organism

Question 2

Why are biofuels (in theory) carbon neutral?

Answer 2

The carbon dioxide taken in by the living organism can balance the amount released when it is burned

Question 3

How does hydroelectric power work?

Answer 3

-Water is collected in a reservoir at the top of a hill
-As the water flows downhill, it turns turbines connected to generators at the bottom

Question 4

How does geothermal energy work?

Answer 4

-Cold water is pumped deep into the Earth, and is heated and evaporated into steam
-The steam drives turbines above the ground, and will activate a generator

Question 5

List some disadvantages of using nuclear power:

Answer 5

-Radioactive waste needs to be stored for centuries
-Power station accidents can make surroundings uninhabitable for many years

Question 6

List some disadvantages of renewable energy:

Answer 6

-Cannot currently meet demands
-Most are not available all the time/unreliable
-Some can cause visual pollution
-Solar cells need to cover large areas

Question 7

In terms of demand, what is an advantage of using gas-fired power stations?

Answer 7

They can meet variations in demand

Question 8

How can fossil fuels be used to generate electricity?

Answer 8

The chemical store of the fuel is transferred to the thermal store of water, which transfers energy to the kinetic store of a turbine. The turbine transfers energy to the kinetic store of a generator, and energy is transferred electrically to the National Grid

Question 9

What fossil fuel is petrol derived from?

Answer 9

crude oil