Energy efficiency - P1 Flashcards
1
Q
What is the equation for efficiency?
A
useful energy output
Efficiency = _______________ x 100
total energy input
2
Q
What is efficiency?
A
Efficiency measures how much energy is wasted and how much is useful. It is measured as a percentage.
3
Q
A kettle uses 100J of energy. 76J of this energy goes into heating the water and 24J of energy goes into heating the surroundings.
How efficient is the kettle?
A
Useful output = heating the water (76J)
Total output = 100J
Efficiency = 76 / 100 = 76%
