During testing, a ceramic power resistor becomes hotter than its surroundings. Engineers want it to emit infrared radiation at a greater rate. Which statement gives the best choice of surface finish?
A shiny silver finish, because a poor absorber of infrared is a good emitter.
Any finish, because objects at the same temperature emit infrared at the same rate.
A matt black finish, because a good absorber of infrared is also a good emitter.
A shiny white finish, because the infrared it reflects adds to the infrared it emits.
106 exam-style questions on AQA GCSE Physics 6.3 Black body radiation, covering 6.3.1 Emission and absorption of infrared radiation and 6.3.2 Perfect black bodies and radiation. Each one has a worked solution and a mark scheme showing where the marks go.