Energy efficiency

Question 1

What is efficiency?

Answer 1

Efficiency is a measure of how much wasted energy is produced compared to useful energy. An efficient object is one which produces more useful energy than wasted.

Question 2

What is the calculation(s) for efficiency?

Answer 2

total energy/power in

Question 3

What is the name for this diagram?

Answer 3

Sankey Diagram

Question 4

What do Sankey diagrams allow us to do?

Answer 4

Sankey diagrams are a visual representation of how much energy is input into a system and what proportion is useful or wasted.
It is the width of the arrows that tell us how much energy is useful or wasted

Question 5

What does the amount of energy transferred by an appliance depend upon?

Answer 5

The amount of energy an appliance transfers depends on how long the appliance is switched on for and the power it draws.

Question 6

What energy transfers does a television give?

Answer 6

light (useful energy)
sound (useful energy)
kinetic (wasted energy)

Question 7

What energy transfers does a hairdryer give?

Answer 7

heat (useful energy)
kinetic (useful energy)
sound (wasted energy

Question 8

What energy transfers does a tumble dryer give?

Answer 8

heat (useful energy)
kinetic (useful energy)
sound (wasted energy)