Physics - Generating electricity

Question 1

What is biomass energy

Answer 1

Biomass energy is generated from decaying plant or animal waste

Question 2

What are the advantages of biomass and wood

Answer 2

cheap
sustainable
They absorb the same amount of CO2 from the atmosphere while growing as they release when they are burned.

Question 3

What are the disadvantages of biomass and wood

Answer 3

give off atmospheric pollutants, greenhouse gasses released, trees absorb CO2 but it’s released when burned

Question 4

What are the advantages of wind energy

Answer 4

renewable energy source, no fuel costs, no polluting gasses produced

Question 5

What are disadvantages of wind energy

Answer 5

wind farms noisy, unreliable, manufacture of wind farms is costly, no wind = no electricity

Question 6

What is tidal power

Answer 6

Water from estuaries getting forced through gaps in a tidal barrage to make use of kinetic energy. Electricity generators in the barrage are driven by water rushing through tubes.

Question 7

What is hydroelectric power

Answer 7

A dam is built across a river valley. Water high up behind the dam gains gravitational potential energy. This is transferred into kinetic energy as the water rushes through the tubes inside the damn. Electric generators inside get driven by the moving water.

Question 8

What are the advantages of water energy

Answer 8

renewable, no fuel costs, no polluting gasses produced, reliable, easily switched on (tidal and hydroelectric)

Question 9

What are the disadvantages of water energy

Answer 9

hydroelectric dams flood farmland and push people from homes, tidal barrages destroy habitats, rotting vegetation underwater releases greenhouse gasses

Question 10

What are solar cells

Answer 10

solar cells are devices that convert light energy directly into electrical energy.

Question 11

How do solar panels work

Answer 11

Cold water is pumped up to the solar panel. Then it heats up and is transferred to a storage tank. A pump pushes cold water from the storage tank through pipes in the solar panel. The water is heated by heat energy from the Sun and returns to the tank.

Question 12

What are the advantages of solar energy

Answer 12

renewable, no fuel costs, no polluting gasses produced

Question 13

What are the disadvantages of solar energy

Answer 13

expensive, inefficient, don’t work at night

Question 14

What are fossil fuels

Answer 14

They were formed from the remains of living organisms millions of years ago and they release heat energy when they are burned. They have chemical energy stored within them.

Question 15

What are some examples of fossil fuels

Answer 15

coal, oil, natural gasses

Question 16

What are the advantages of fossil fuels

Answer 16

cheap, obtainable, much of our infrastructure is designed to run using fossil fuels.

Question 17

What are the disadvantages of fossil fuels

Answer 17

non-renewable, release sulphur dioxide gas when they burn, contributes to acid rain, release carbon dioxide when burned, adds to the greenhouse effect and global warming

Question 18

What are the main nuclear fuels

Answer 18

The main nuclear fuels are uranium and plutonium.

Question 19

How does nuclear power work?

Answer 19

heat is used to change water into steam in the boiler
the steam drives the turbine (heat to kinetic energy)
this drives the generator to produce electricity – kinetic to electrical energy

Question 20

What are the advantages of nuclear power

Answer 20

don’t produce carbon dioxide or sulphur dioxide, reliable sources of energy, 1 kilogram of nuclear fuel produces millions of times more energy than 1 kilogram of coal

Question 21

What are the disadvantages of nuclear power

Answer 21

non-renewable, huge risk if accident occurs,

Question 22

What is the order of start-up time for different fuels

Answer 22

gas-fired station (shortest start-up time)
oil-fired station
coal-fired station
nuclear power station (longest start-up time)

Question 23

How do conventional power stations work?

Answer 23

The fuel is burned to boil water to make steam
The steam makes a turbine spin
The spinning turbine turns a generator which produces electricity
The electricity goes to the transformers to produce the correct voltage

Question 24

What are the features of the national grid

Answer 24

power station-step up transformer-high voltage transition lines-step down transformer-consumers

Question 25

How do wind turbines work?

Answer 25

Wind turbines use the wind to directly drive turbines. They have huge blades mounted on a tall tower. The blades are connected to a nacelle, or housing, which contains gears linked to a generator. As the wind blows, it transfers some of its kinetic energy to the blades, which turn and drive the generator.

Question 26

What does a fuse look like?

Answer 26

Rectangle with line through it.

Question 27

What does a battery/cell look like?

Answer 27

big vertical line - space - small vertical line

Question 28

What does a lamp look like?

Answer 28

Circle with cross in middle

Question 29

What does a resistor look like?

Answer 29

Rectangle with no line going through it.

Question 30

What does a light dependent resistor look like?

Answer 30

Rectangle in a circle with two arrows pointing into the circle.

Question 31

What does a thermistor look like?

Answer 31

Rectangle with diagonal line going through and flat bit at the the bottom. _/

Question 32

What does a variable resistor look like?

Answer 32

Rectangle with diagonal arrow going through it.

Question 33

What does a diode look like?

Answer 33

circle with a triangle pointing at a vertical line inside it.

Question 34

What does a LED look like?

Answer 34

circle with a triangle pointing at a vertical line inside it and two arrows pointing out of the circle.

Question 35

What does an a.c power supply look like?

Answer 35

–o ~ o–

Question 36

What does a d.c power supply look like?

Answer 36

–o o– with +and- above circles.

Question 37

What does a variable d.c power supply look like?

Answer 37

–o / o– (/ is an arrow) with + and - above circles.