P1.2 Using Energy Flashcards

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1
Q

What energy is transferred from a light bulb?

A

Thermal and light energy

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2
Q

How do you calculate energy?

A

Energy (kWh) = power (w) x time (h)

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3
Q

what are nine types of energy?

A

electrical, light, sound, kinetic, nuclear, thermal, gravitational potential, elastic potential, chemical energy.

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4
Q

what are gravitational potential energy, elastic potential and chemical energy forms of?

A

stored energy as they are waiting to be turned into one of the other forms.

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5
Q

how do you calculate the efficiency of a machine?

A

useful energy out divided by total energy in.

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6
Q

what do the arrows pointing down in a Sankey diagram represent?

A

The waste energy.

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7
Q

what are the stages of burning non-renewable sources of energy in a power station?

A

coal is burnt to release heat. Water is heated in the boiler and turned to steam. Steam rushes through turbine and makes it spin which turns the generator too. Electricity is produced by the spinning generator.

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8
Q

what are the four stages of energy transfers in a power station?

A

Chemical energy into heat energy into kinetic energy into electric energy.

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9
Q

why might people object to wind turbines being put up near where they live?

A

destroys the view, loud, harmful to animals.

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10
Q

what are three advantages of wind turbines?

A

renewable resource, no fossil fuels produced, running costs are low.

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11
Q

why are renewable sources of often used for small-scale production of electricity?

A

they are a good source of energy in situations where only a small amount of electricity is needed. E.g. calculators

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12
Q

State the types of energy.

A

Magnetic, Kinetic, Heat (Thermal), Light, Gravitational Potential, Chemical, Sound, Electrical, Elastic Potential, Nuclear

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13
Q

How do you calculate efficiency as a decimal?

A

Amount of useful energy/total energy

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14
Q

How do you calculate efficiency as a percentage?

A

(Amount of useful energy/total energy) x 100

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15
Q

what are the two advantages of hydroelectric power?

A

renewable, gives us free energy

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16
Q

what are two disadvantages of hydroelectric power?

A

The set up the costs are high and it destroys wildlifes habitat

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17
Q

hydroelectric power stations deliver energy when…?

A

it is needed

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18
Q

pumped storage power stations deliver energy that…?

A

they have previously stored

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19
Q

how does a tidal barrage work?

A

The tide comes in and water passes through the turbines. This builds up behind the barrage. When the tide goes out the water is allowed out through the turbine in the barrage at controlled speed. as the water passes through the turbines electricity is generated

20
Q

why many people object to tidal barrage is being built?

A

initial costs are high, look unattractive & can prevent access for boats.

21
Q

how does the wave powered generators work

A

wave moves water upwards forcing air out. The moving air makes the turbine spin. The spinning generator makes electricity. The spinning turbine drives a generator. The water goes down again and air is sucked downwards spinning the turbine the other way and generating more power

22
Q

what are you problems with wave power?

A

high initial costs, spoil the view, depends on the wind so can be unreliable.

23
Q

biofuels are used to generate electricity in a similar way to…?

A

fossil fuels

24
Q

how is electricity generated using geothermal energy?

A

in some volcanic areas hot water and steam rise to the surface this steam can be used to drive turbines to generate electricity.

25
Q

why is burning biofuels carbon neutral?

A

plants are used to produce biofuels therefore they are absorbing carbon dioxide from the atmosphere so no extra carbon dioxide is being burnt

26
Q

what is meant by carbon capture?

A

collecting carbon dioxide from power stations before it’s released into the atmosphere

27
Q

how can captured carbon dioxide be stored?

A

empty gas fields, dissolved in sea water at the bottom of the ocean

28
Q

what equipment do you need for high-voltage transmission?

A

step up transformer, pylons

29
Q

why is it still cheaper to use high voltages for transmission?

A

less energy is wasted as heat so it saves more money

30
Q

The National Grid transmit energy at…. voltage and….current?

A

high voltage and a low current

31
Q

what are two ways the National Grid can increase the supply of electricity they are being demanded?

A

more plants can be built or the power output power plants can be increased

32
Q

the lower the U-value the better…?

A

the insulator

33
Q

how many J in a KJ?

A

1000

34
Q

how do you work out energy transferred in kWh?

A

power (kW) X time (H)

35
Q

how do biofuels work?

A

light energy taken in from photosynthesis in turned to chemical energy

36
Q

what are disadvantages of biofuels?

A

land could be used to grow food crops

harming wildlife habitats

37
Q

how do hydroelectric power work?

A

water trapped behind dam - falls down hill & turns generator which turns turbine

38
Q

what are the energy transfers in hydroelectric power?

A

gravitational potential energy - kinetic energy - electrical energy

39
Q

how does nuclear power work?

A

uranium and plutonium undergo nuclear fission releasing heat energy - converts water into stream

40
Q

does nuclear power produce carbon dioxide?

A

No

41
Q

what is the national grid made up of?

A

transformers & cables

42
Q

what are transverse waves?

A

light, x-ray, infrared

43
Q

which have a higher frequency, radio waves or gamma waves?

highest energy?

A

gamma rays

44
Q

what is the definition of a virtual image?

A

cannot be projected onto a screen

45
Q

why does the light bend towards the normal line when going through glass?

A

it slows down therefore it bends but speeds up when it has passed through the glass - refraction

46
Q

how can mobile phones be dangerous?

A

releases microwave radiation which can be absorbed by the head which could heat the body cells