Planck’s law holds good for

A. Black bodies

B. Polished bodies

C. All coloured bodies

D. All of the above

Answer: Option A

Solution(By Examveda Team)

Planck's law is a formula for the spectral radiance of an object at a given temperature as a function of frequency (Lf) or wavelength (Lλ).
Planck’s law holds good for black bodies.
It has dimensions of power per solid angle per area per frequency or power per solid angle per area per wavelength.