A black metal foil is warmed by radiation from a small sphere at temperature 'T' and at a distance 'd'. It is found that the power received by the foil is P. If both the temperature and distance are doubled, the power received by the foil will be :
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Question

A black metal foil is warmed by radiation from a small sphere at temperature 'T' and at a distance 'd'. It is found that the power received by the foil is P. If both the temperature and distance are doubled, the power received by the foil will be :

Options

G1 Physics · Accepted Answer

Use Stefan-Boltzmann law P=eσA(T⁴−Tₛ⁴), Wien's law λₘT=b, or Newton's law of cooling dθ/dt=−k(θ−θₛ), as applicable. Evaluating the given data/statements gives B: 4 P. Therefore the correct answer is B.