P3 Flashcards
1
Q
What are the main primary energy sources that humans use?
A
Fossil fuels (oil, coal, gas) nuclear fuel (uranium) Biofuels wind waves sunlight
2
Q
Why is electricity a secondary energy source?
A
Primary energy sources need to transfer their energy to create electricity.
3
Q
What fuel leads to climate change?
A
Burning fossil fuels as they release carbon dioxide
4
Q
What unit is used to measure power?
A
(W) - watts
5
Q
How can we reduce the amount of electricity we use?
A
Person
- Use high efficiency A-rated appliances
- turn off components when you don’t need them
- not boiling more water than necessary and cooking food in a microwave oven
Nation
- using efficient cars
- living in houses that have better insulation
- building more efficient power stations and improving output of old power stations
6
Q
What is mains electricity produced by?
A
generators
7
Q
How do generators produce a voltage?
A
It produced a voltage across a coil of wire by spinning a magnet near it
8
Q
How power stations work?
A
- coal (fuel source) burnt in furnace
- water heated to produce steam
- jet of steam turns turbine
- turbine spins generator
- electricity produced by generator
9
Q
How does a nuclear power station make high pressure steam?
A
- fuel rods are put close to each other in the reactor so that they heat up
- taking away the heat with high pressure water circulating the rods
- using the high pressure water to boil low pressure water in a boiler
10
Q
Why is waste from a nuclear power station dangerous?
A
Nuclear waste is radioactive
It can ironies cells
