Efficiency
Physics: Cambridge International GCSE Supplement, topic 1.11.11
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 Efficiency
Which of these quantities is considered in the equation for efficiency?
How is efficiency most often expressed?