Conservation and Dissipation of Energy Practice Questions

Question 1

Give 2 reasons for taking repeat readings in an investigation

Answer 1

reduce random errors
calculate a mean

Question 2

Answer 2

as sepeed increases, efficiency increases
appears to reach a limit

Question 3

Give the mainway a motor is likely to waste energy

Answer 3

heating the surroundings

Question 4

geothermal

Answer 4

Energy from the earth’s core is used to heat water

Question 5

biofuel

Answer 5

gases from rotting plant material are burned to heat water

Question 6

Why do countries continue generating large amounts of electricity using nuclear power stations instead of using non-renewable energy sources?

Answer 6

more reliable than renewable energy resources
setting up renewable energy sources cost a lot, infrastructure for power stations already exist

Question 7

disadvantages of generating electricity using nuclear power stations

Answer 7

non-renewable
long start-up time
produces nuclear waste

Question 8

Answer 8

the higher the efficiency, the higher the cost (per m2 to manufacture)

Question 9

Answer 9

loft insulation costs the least to install
double glazing cost the mosy

loft insulation is the most cost effective long term, pay back time is 2 years
double glazing is the least cost effective, pay back 100 years

double glazing won’t pay for itsel in your lifetime and is ineffective for insulation purposes