Loft insulation is fitted in the roof of a house.
How does loft insulation reduce unwanted energy transfer?
It has a high thermal conductivity, so energy passes through it at a lower rate
It has a low thermal conductivity, so energy passes through it at a lower rate
It absorbs energy from the house and keeps it in its thermal store for ever
It has a low thermal conductivity, so energy passes through it at a higher rate
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.