efficiency (topic 1)

Question 1

(2)

Answer 1

temperature (increase) and time switched on are directly proportional

Question 2

(2)

Answer 2

• lead
• needs least energy to raise temperature by 1°C

Question 3

what happens to the energy that is not usefully transferred by the solar cells (1)

Answer 3

wasted

Question 4

suggest one advantage of the aircraft having fuel cells as well as the solar
cells

Answer 4

• can fly at night
• can fly in the winter
• can fly faster

Question 5

give one environmental advantage of using electric motors to drive the
aircraft propellers rather than motors that burn a fuel

Answer 5

produces no (pollutant) gases

Question 6

• eventually, the designers want to produce an unmanned aircraft that can fly at twice the height of a passenger jet for up to six months
• suggest one possible use for an aircraft such as this

Answer 6

• weather forecasting
• spying

Question 7

Answer 7

generator

Question 8

Answer 8

Question 9

give one disadvantage of using a wind generator to charge a battery

Answer 9

• wind speed may be too low to operate the generator
• wind may not always blow