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Question 1

What tare the 8 energy stores?

Answer 1

• Thermal energy store.
• Kinetic energy store
• Gravitational potential energy store
• Elastic energy stores.
• Chemical energy stores
• Nuclear energy stores
• Electromagnetic energy stores- two objects will have energy in this store if they exert a magnetic force on each other.
• Electrostatic energy stores- two objects will have energy in this store if they exert an electrostatic force on eachother.

Question 2

Conduction:

Answer 2

Conduction is where the vibrating particles of a substance transfer energy to neighbouring particles.

Question 3

Convection:

Answer 3

Convection is where the energetic particles of a substance move away from hotter to cooler regions.

Question 4

Work done also is

Answer 4

energy transferred (they mean the same thing)

Question 5

What are the two types of way work can be done?

Answer 5

work can be done mechanically or electrically.

Question 6

The conservation of energy says that:

Answer 6

Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed.

Question 7

What happens when energy is transferred between stores?

Answer 7

When energy is transferred between stores, not all the energy is transferred usefully to the store that you want, some of it is dissipated. (Usually to the thermal energy stores of the surroundings.)

Question 8

What measurement is energy usually measured in?

Answer 8

Energy is usually measured in Joules however for electrical devices it might be given in kilowatt-hours.

Question 9

No device is ever…

Answer 9

…100% efficient, because whenever work is done, some of the energy transferred is always wasted. The less energy that is “wasted”, the more efficient the device is said to be.

Question 10

Efficiency=

Answer 10

Useful energy transferred / total energy transferred.

Question 11

How can the efficiency of any energy transfer increased?

Answer 11

The efficiency of an energy transfer can be increased by reducing the amount of unwanted energy transfer. An example of this might be lubrication on a motor.

Question 12

How can you reduce energy loss in buildings?

Answer 12

To reduce the amount of energy lost in buildings you can use thermal insulation. For example: Loft insulation, thick curtains.
Also the thickness of wall determines the rate of energy transfer. So the thicker the walls the lower the rate of energy transfer

Question 13

What do Sankey diagrams help show?

Answer 13

Sankey diagrams summarise all the energy transfers taking place in a process. The thicker the line or arrow, the greater the amount of energy involved.

Question 14

What are the two types of energy resources?

Answer 14

Energy resources can either be renewable or non-renewable.

Question 15

What type of energy resource do humans usually get their energy from?

Answer 15

Humans tend to get most of their energy from non-renewable sources, which means they will run out one day.

Question 16

What are the 3 main fossil fuels on Earth?

Answer 16

The 3 fossil fuels are:
-Coal
-Oil
Gas

Question 17

What is an advantage of using fossil fuels to generate energy?

Answer 17

An advantage of using fossil fuels to generate energy is that they are reliable and fast. Also the resources are extracted from the Earth at a quick enough rate to keep up with the demand from humans

Question 18

What are the disadvantages of using fossil fuels?

Answer 18

A disadvantage of using fossil fuels is that they damage the environment when they’re used. They also contribute to the greenhouse effect as when they are burnt CO2 is released into the atmosphere, which results in an increase in global warming.

Question 19

Renewable energy:

Answer 19

Renewable energy is one that will never run out. Most of them still do damage the environment but in a much less nasty way than non-renewable energy resources.

Question 20

What are the main renewable energy resources?

Answer 20

The main renewable energy resources are bio fuels, wind, hydroelectricity and the tides.

Question 21

How is power generated inside a power station?

Answer 21

1. As the fossil fuel burns the water is heated.
2. The water boils to form steam, which moves and turns a turbine.
3. The turbine is connected to an electrical generator, which generates a potential difference across (and so a current through) a wire by spinning a magnet neat to the wire.
4. The current produced by the generator flows through the national grid.

Question 22

What is solar power?

Answer 22

Solar power is power obtained by harnessing the energy of the sun’s rays.

Question 23

Where is solar power most often used?

Answer 23

Solar power is often used in remote places where there’s not much choice to power electric road signs and satellites. The initial costs are pricey however after that the energy is free.

Question 24

What are bio fuels made up from?

Answer 24

Bio fuels are made from plants and waste and they are a renewable energy resource because we can just grow them.

Question 25

Why are bio fuels okay to burn?

Answer 25

Bio fuels are okay to burn because even though when they are burnt they release CO2; the plants that you grow or remove CO2 from the atmosphere anyways so there is no net change of CO2 in the atmosphere.

Question 26

What is hydroelectricity?

Answer 26

Hydroelectricity is electricity produced from hydropower, through the use of dams and flooding valleys.

Question 27

Advantage of hydroelectricity:

Answer 27

A big advantage of the use of hydroelectricity is that it is easy to create more or less electricity by letting more or less water going through the turbines. It is also another reliable source of energy.

Question 28

Disadvantage of hydroelectricity:

Answer 28

A disadvantage of hydroelectricity is that there is a big impact on the environment due to the flooding of the valley and possible loss and destruction to habitats.

Question 29

What is the national grid?

Answer 29

The national grid is a giant web of wires and transformers that covers the UK and connects power stations to consumers.

Question 30

What are the two types of electric current:

Answer 30

The two types of electric current are:

• Alternating currents
• Direct currents

Question 31

What are alternating currents produced by?

Answer 31

Alternating currents are produced by alternating voltages in which the positive and negative ends of the potential difference keep alternating.

Question 32

What 3 coloured wires are usually inside a plug?

Answer 32

• Blue wire
• Brown wire
• Green or yellow wire

Question 33

What is the blue wire?

Answer 33

The blue wire is the neutral wire. The neutral wire completes the circuit- electricity normally flows in through the live wire and out through the neutral wire. Neutral wire is always at 0 V.

Question 34

What is the brown wire?

Answer 34

The brown wire is the live wire. The live wire carries the voltage (potential difference). It alternates between a high positive and negative voltage if about 230 V.

Question 35

What is the green wire?

Answer 35

The green wire is the Earth wire. The Earth wire is for safety. It carries the current away if something goes wrong. It’s also at 0 V.