An infrared motion sensor contains an internal baffle that behaves as a perfect black body. Radiation from the surroundings is incident on the baffle.
Which statement is correct?
The baffle absorbs all radiation incident on it but does not emit radiation itself.
The baffle reflects all radiation incident on it and is the best possible emitter.
The baffle absorbs incident infrared radiation but reflects radiation at all other wavelengths.
The baffle absorbs all radiation incident on it and is the best possible emitter.
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.