Which statement describes what happens when energy is dissipated?
Energy is destroyed, so the total energy decreases
Energy moves to a store where it is easy to use again
Energy spreads out and is stored in less useful ways
Energy is changed into mass, so the system gets heavier
50 exam-style questions on OCR GCSE Physics 7.2 Power and efficiency, covering 7.2.1 Dissipation of energy, 7.2.2 Energy transfers in domestic devices, 7.2.3 Power ratings of domestic appliances, 7.2.4 Efficiency of energy transfers, 7.2.5 Ways to increase efficiency, 7.2.6 Reducing unwanted energy transfers, and 7.2.7 Thermal conductivity and the cooling of buildings. Each one has a worked solution and a mark scheme showing where the marks go.