Energy Efficiency
Physics: AQA GCSE Higher, topic 1.2.2
Efficiency of Energy Transfer
The efficiency of an energy transfer can never be more than 100.
Efficiency (energy in joules)
- Efficiency = (useful energy output/total energy input) x 100.
- The useful energy output and total energy input are measured in joules (J).
Efficiency (power in watts)
- Efficiency = (useful power output/total power input) x 100.
- The useful power output and total power input are measured in watts (W).
Efficiency of Energy Transfer
The efficiency of an energy transfer can never be more than 100. It is defined below:
Efficiency (energy in joules)
- Efficiency = (useful energy output/total energy input) x 100.
- The useful energy output and total energy input are measured in joules (J).
Efficiency (power in watts)
- Efficiency = (useful power output/total power input) x 100.
- The useful power output and total power input are measured in watts (W).
Test yourself on Energy Efficiency
How is efficiency most often expressed?
Which of these quantities is considered in the equation for efficiency?