Aqa Gcse Physics Unit 1

Front 1

When is heat energy transferred quickly?

Back 1

When there's a large temperature difference between a body and its surroundings

Front 2

Why does a liquid's average temperature decrease as the liquid evaporates?

Back 2

Because the particles with the highest energy evaporate first, leaving the low-energy particles behind, decreasing the liquid's average temperature

Front 3

Describe the particles in a solid

Back 3

They have little energy and strong forces of attraction between them, so they stay close together in a fixed, regular arrangement

Front 4

Why are metals good conductors?

Back 4

Because they have free electrons which collide and transfer their energy more rapidly

Front 5

What is an 'effective' method of insulation?

Back 5

One that gives the largest annual saving

Front 6

What is a 'cost-effective' method of insulation?

Back 6

One that has the shortest payback time

Front 7

What do U-values tell us?

Back 7

How quickly heat can transfer through a material

Front 8

Do insulators have high or low U-values?

Back 8

Low

Front 9

What is an object's specific heat capacity?

Back 9

How much energy it can store

Front 10

What is the unit for specific heat capacity?

Back 10

J/Kg⁰C

Front 11

Why do heaters have a high specific heat capacity?

Back 11

So they can store lots of heat energy

Front 12

What is the equation for efficiency?

Back 12

Useful Energy Out / Total Energy In

Front 13

What is a kWh?

Back 13

The amount of electrical energy used by a 1 kW appliance in an hour

Front 14

How can access to electricity improve someone's standard of living?

Back 14

They can power refrigerators to keep food fresh and use phones and computers to receive information

Front 15

What are the four non-renewable energy resources?

Back 15

Coal, oil, natural gas and nuclear

Front 16

Name three renewable energy resources

Back 16

Wind power, solar power and hydroelectric

Front 17

How do non-renewable power stations generate electricity?

Back 17

The fossil fuel is burned, then this heat is used to heat water to produce steam, which turns a turbine that powers a generator

Front 18

Give one advantage of gas power stations

Back 18

They don't use water, so have a quick start-up time

Front 19

How do nuclear reactors produce heat?

Back 19

Through nuclear fission

Front 20

How does a hydroelectric power station generate electricity?

Back 20

Water flows down a valley, turning a turbine as it goes past

Front 21

What is the environmental disadvantage to hydroelectric power?

Back 21

A valley is flooded, which rots vegetation and causes the release of methane and carbon dioxide

Front 22

What is pumped storage?

Back 22

When water is pumped back to the upper reservoir at times of low demand so that it can be released at peak demand

Front 23

How does wave power generate electricity?

Back 23

The motion of the waves is used to drive a generator

Front 24

How do tidal barrages generate electricity?

Back 24

The tide causes water to fill up estuaries, turning turbines as it passes through dams

Front 25

What are the problems with tidal barrages?

Back 25

They prevent access by boat and can alter the habitats of wildlife

Front 26

Where does geothermal energy come from?

Back 26

Hot rocks fairly near the surface

Front 27

What is the difference between fossil fuels and biofuels?

Back 27

The organisms used to make biofuels were living much more recently

Front 28

How is ethanol produced?

Back 28

By fermenting crops such as sugar cane

Front 29

What is the main problem with nuclear power?

Back 29

The nuclear waste is very difficult to dispose of

Front 30

What is the advantage of biofuels?

Back 30

They are carbon neutral

Front 31

What are the disadvantages of biofuels?

Back 31

Deforestation usually occurs and the burning of the vegetation releases carbon dioxide and methane

Front 32

What is carbon capture?

Back 32

Where the carbon dioxide from power stations is collected and pumped into underwater gas and oil fields

Front 33

What is the national grid?

Back 33

A network of pylons and cables that covers the whole of Britain

Front 34

Why is a high voltage chosen over a high current for disturbing electricity via the national grid?

Back 34

A high current means that lots of energy is lost as heat through the cables

Front 35

What is the job of transformers?

Back 35

To step-up the voltage at one end and step it down again at the other

Front 36

How can the increasing demand for electricity be met?

Back 36

By opening more power plants or increasing their output

Front 37

How can demand for electricity be reduced?

Back 37

By consumers using more energy efficient appliances and being more careful not to waste energy

Front 38

When are waves diffracted most?

Back 38

When passing through a small gap

Front 39

Why are long-wave radio waves used for communication?

Back 39

They can diffract around the curved surface of the Earth

Front 40

How can shorter wave radio waves be received over long distances?

Back 40

By bouncing them off of the ionosphere

Front 41

Why are microwaves used for satellite communication?

Back 41

Because they can penetrate the Earth's atmosphere

Front 42

What are infrared waves used for?

Back 42

Remote controls and optical fibres

Front 43

Give a use of visible light

Back 43

Photography