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Explain Planck radiation law

Planck radiation law: The law which explained blackbody radiation better than its precursor, therefore resolving the ultraviolet catastrophe. This is based on the supposition that electromagnetic radiation is quantized.

For a blackbody at thermodynamic temperature T, the radiance R over a range of frequencies between the nu and nu + dnu is specified by:

R = 2 pi h nu3/[c3 [exp (h nu/k T) - 1]].

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