Efficiency

• Formula for efficiency?

  Efficiency = useful energy output / total energy input

  Efficiency = useful power output / total power input
• Efficiency is usually given in a decimal eg 0.6

  How to convert to percentage?

  X 100
• Government recommended sale of filament lamps should be banned.

  Why?

  Inefficient
• How could a bicycle be made more efficient?

  Add some oil to the chain.