P2d-fuels for power

Question 1

What fuels are used in power stations?

Answer 1

• fossil fuels
• renewable biomass(wood, straw and manure)
• nuclear fuels (uranium, plutonium)

Question 2

What are the units for power?

Answer 2

Watt or kilowatt

Question 3

What does the cost of using expensive electrical appliances depend on?

Answer 3

• power rating in watts and kilowatts

- the length of time it is switched on

Question 4

What are the advantages of using off peak electricity?

Answer 4

• cost effective for electricity company since power stations cant be turned off at night
• cheaper for consumers if they buy electricity during the off peak hours

Question 5

What are the disadvantages of using off peak electricity?

Answer 5

• increased risk of fire (appliances on no one watching)

- start to fit routine around cheap rate hours(stop enjoying use of electricity during the day)

Question 6

Why are transformers used in the national grid to increase the voltage?

Answer 6

Electrical energy is transmitted at high voltage to reduce energy waste and costs

Question 7

What do step up transformers do and why do they allow better efficiency?

Answer 7

• increase voltage
• decrease current
• low current means less electrical energy lost as heat energy(better efficiency)

Question 8

What do step down transformers do and why are they needed?

Answer 8

• decrease voltage

- so it is safe to use in our homes

Question 9

How do fuels release energy?

Answer 9

They release energy as heat