Electricity Generation

Question 1

How is electricity generated?

Answer 1

Moving a magnet inside coil of wire

Question 2

What is electromagnation?

Answer 2

When magnet is moved in & out of coil, current is generated

Question 3

How can we induce more electric current?

Answer 3

Use stronger magnet
Use coil wire with mor turns on magnet
Move magnet faster

Question 4

What is the first step for a power station to produce energy?

Answer 4

Fuel burned to produce heat in burner

Chemical energy in fossil fuels transferred to heat energy

Question 5

What is the second step for a power station to produce energy?

Answer 5

Heat used to turn water into steam through boiler

Heat energy used to boil water, forming steam & kinetic energy

Question 6

What is the third step for a power station to produce energy?

Answer 6

Steam drives turbine, which is connected to generator

Kinetic energy of steam transferred to kinetic energy of turbine which drives generator

Question 7

What is the fourth step for a power station to produce energy?

Answer 7

Rotating generator makes electricity

Kinetic energy -> electrical energy

Question 8

What is the energy flow diagram in a a power station?

Answer 8

Chemical energy & fossil fuels
/. -> heat & sound
Kinetic energy (or heat) in steam
/. -> heat & sound
Kinetic energy in turbine.
/. -> heat & sound
Electricity energy from generator

Question 9

What parts do all transformers have?

Answer 9

Primary coil
Secondary coil
Iron core

Question 10

What is a primary coil?

Answer 10

The input voltage is connected across this coil

Question 11

What is a secondary coil?

Answer 11

The output voltage is across secondary coil

Question 12

What is an iron core?

Answer 12

Links coils magnetically, no current flows in iron core

Question 13

What are the 2 types of transformers?

Answer 13

Step-up & step-down

Question 14

What is a step-up transformer?

Answer 14

Found after generator in power station, but before grid

Question 15

What is a step-down transformer?

Answer 15

Before electricity comes into our homes

Question 16

What does a step-up transformer do?

Answer 16

Increases voltage
Decreases current (to reduce heat loss)
Has more turns on the secondary coil than primary coil
Has thinner, cheaper wires

Question 17

What does a step-down transformer do?

Answer 17

Decreases voltage
Increases current
Has more turns on primary coil than second coil

Question 18

What is the definition of non-renewable energy? Examples?

Answer 18

An energy source that has a finite supply
Fossil fuels
Nuclear energy
Biomass

Question 19

What is the definition of renewable energy? Examples?

Answer 19

Energy which is collected from resources that will never run out or that are naturally replenished during human lifetime 
Light 
Wind 
Rain 
Waves

Question 20

What are fossil fuels?

Answer 20

Formed from remains of dead plants & animals subjected to high temperatures & pressures over millions of years in the earth’s crust, e.g. Coal, oil & gas

Question 21

What is nuclear energy?

Answer 21

Based on unclear fission, it relies on uranium ore which will run out

Question 22

What is biomass?

Answer 22

Uses energy from combustion of wood & is non-renewable if plants aren’t regrown

Question 23

What are advantages & disadvantages of wind energy?

Answer 23

Method - blades of wind turbine rotate & drive a generator
Adv- cost effective once built, unlimited supplies of wind
Dis- only works when wind blows, noisy & unsightly

Question 24

What are the advantages & disadvantages of wave energy?

Answer 24

Method - forces of waves drive turbine linked to generator
Adv - cost effective once built, unlimited supply of wave energy
Dis - expensive to install, relatively inefficient

Question 25

What are the advantages & disadvantages of light/solar energy?

Answer 25

Method - Solar cells use sun’s energy to enervate electricity
Adv - cost effective once built, unlimited supply of light energy
Dis - expensive to install, can be unreliable due to weather