Energy Efficiency (Physics) 4 Flashcards
@Explain the term ‘energy efficiency’. @Calculate, using the energy efficiency equation. @ Compare and evaluate light bulbs with different efficiencies.
1
Q
What does energy efficiency mean?
A
Energy efficiency means using less energy to achieve the same results.
2
Q
What is the Law Of Conservation?
A
Energy cannot be created nor destroyed, it can only be transferred from one form to another.
3
Q
State the equation used to calculate energy efficiency?
A
Efficiency = useful energy output / total energy input (J)
4
Q
Tom burnt 80J of wood to stay warm, he gained 60J of heat and 20J of light. Calculate its efficiency.
A
75 %
