An electric kettle supplies 150 000 J150\,000\text{ J}150000 J of energy, but only 112 500 J112\,500\text{ J}112500 J of this energy is actually transferred to heat the water.
Calculate the efficiency of the kettle.
Use the equation:
efficiency=useful energy transferredtotal energy supplied \text{efficiency} = \frac{\text{useful energy transferred}}{\text{total energy supplied}} efficiency=total energy supplieduseful energy transferred38 exam-style questions on Edexcel GCSE Physics 3.2 Dissipation and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.