A student compares the absorption of infrared radiation by two metal plates with different surface finishes. Which pair of variables should be kept the same?
surface finish and distance from the heater
plate area and distance from the heater
surface finish and final plate temperature
plate area and final plate 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.