National and global energy resources

Question 1

Where are fossil fuels obtained from

Answer 1

Long-dead biological material

Question 2

What is a biofuel

Answer 2

Any fuel obtained from living/recently living organisms

Question 3

How are biofuels renewable

Answer 3

They can be replaced at the same rate of which they are used up

Question 4

How is biofuel carbon neutral

Answer 4

Carbon taken in as CO2 by living organisms = amount released when burnt

Question 5

Give 3 of 7 examples of biofuels

Answer 5

Any 3 from: 
.waste vegetable oil
.methane
.rapeseed plants
.ethanol
.straw
.nutshell
.woodchip

Question 6

What 3 energy sources have then highest energy demand

Answer 6

1) oil - 31%
2) coal - 31%
3) gas - 24%

Question 7

How does a nuclear reactor work (4 steps)

Answer 7

1) nuclei of uranium atoms are unstable so split which releases energy
2) many uranium nuclei in nuclear reactor
3) energy released used to heat water which becomes steam
4) steam moves a turbine which produces energy

Question 8

Explain how a wave generator works

Answer 8

. Floating turbine in water
. Movement of waves drives turbine round
. Turbine turns a generator
. Electricity delivered to grid through cable

Question 9

How does a hydroelectric power generator work (4 steps)

Answer 9

1) Water collected in reservoir at top of hill
2) When allowed to move downhill, turns turbine connected to generators
3) Water collected at bottom in reservoir
4) Pumped back uphill when demand high to repeat process

Question 10

How does a tidal power station work

Answer 10

1) Water from each high tide trapped behind tidal barrage
2) Water released back into sea through turbines
3) Turbines drive generators

Question 11

What is a solar cell

Answer 11

Flat solid cell —> transfers sun energy directly into electrical

Question 12

What is a solar panel and what can it be used for

Answer 12

1) A large number of solar cells joined together

2) Can generate electricity in remote locations with no access to national grid

Question 13

How does a solar power tower work

Answer 13

1) Thousands of mirror reflect sunlight onto water tank
2) Water heated and steam produced
3) Steam drives turbines which turns generators

Question 14

Where does geothermal energy come from

Answer 14

Energy released by radioactive substances in Earth (only in volcanic or other suitable locations)

Question 15

How does a geothermal power station work

Answer 15

1) Very deep holes drilled
2) Cold water pumped into hot rocks
3) Water comes back to surface as steam
4) Steam used to drive turbines

Question 16

What does burning coa and oil produce and what does it cause

Answer 16

1) Sulphur dioxide

2) Acid rain

Question 17

Give 2 disadvantages of nuclear power

Answer 17

1) Used rods remain radioactive + must be stored safely for centuries
2) One mistake in station could make entire area unsafe

Question 18

Why aren’t renewable energy sources the main energy resources used by man

Answer 18

Would not be able to meet current world demand for energy

Question 19

What is a base load demand and what 2 main energy sources provide it

Answer 19

1) A constant amount of energy always being provided

2) Coal and Nuclear

Question 20

Why does nuclear have a constant base load demand

Answer 20

It has the longest start up time of all energy sources at up to 12 hours

Question 21

What is a renewable energy source

Answer 21

One that can be replenished as it is used

Question 22

Give 4 uses of energy resources

Answer 22

Transport, electricity, generation and heating

Question 23

What 2 forms of unwanted energy is produced from a kettle

Answer 23

1) internal thermal energy heating the kettle

2) infrared radiation lost to the surroundings