Heater X has a power rating of 3.0 kW. Heater Y has a power rating of 1.5 kW.
Each heater is used to heat an identical room for 2 hours.
Which statement is correct?
Y transfers twice as much energy to the thermal store of the room as X
X and Y transfer the same energy, because they are on for the same time
X transfers only 1.5 J1.5\ \text{J}1.5 J more energy to the room than Y does
X transfers twice as much energy to the thermal store of the room as Y
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.