Define efficiency as: (a) (%) efficiency = (useful energy output) / (total energy input) × 100% (b) (%) efficiency = (useful power output) / (total power input) × 100% and recall and use these equations

Recall and use the equation energy = current × voltage × time, E = IVt

Explain everyday applications using ideas about conduction, convection and radiation, including: (a) heating objects such as kitchen pans (b) heating a room by convection (c) measuring temperature using an infrared thermometer (d) using thermal insulation to maintain the temperature of a liquid and to reduce thermal energy transfer in buildings