For a perfectly black body, coefficient of emission is (a) zero (b) infinity (c) unity (d) less than one (non-zero)

Answer: (c). A perfectly black body has a = 1; by Kirchhoff's law its emissivity e = a = 1. So the answer is (c) unity.

For a perfectly black body, coefficient of emission is | MHT CET 2021 (23 Sep, Shift 1)

Q86MHT CET 2021 · 23 SEP · SHIFT 1Easy

Thermal Radiation: Black Body, Stefan & Wien

For a perfectly black body, coefficient of emission is

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Answer: (c)

A perfectly black body has $a = 1$ ; by Kirchhoff's law its emissivity $e = a = 1$ .
So the answer is (c) unity.

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