A student compares infrared emission from two surfaces using the same detector. Surface P gives a larger reading than surface Q. Both surfaces have the same area, but P is hotter. Which conclusion is justified?
P is the better emitter because its reading is larger.
Q is the better emitter because its temperature is lower.
The finishes are equally good emitters because their areas match.
The effect of surface finish cannot be separated from temperature.
96 exam-style questions on Edexcel GCSE Physics 5.3 Black body radiation, covering 5.3.1 Emission of radiation and temperature, 5.3.2 Radiation balance and constant temperature, and 5.3.3 The temperature of the Earth. Each one has a worked solution and a mark scheme showing where the marks go.