The unit of Stefan #39;s constant σ is

Your Ultimate Guide to JEE & NEET Question Solutions

The unit of Stefan's constant $\sigma $ is

A

$W\,{m^{ - 2}}\,{K^{ - 1}}$

B

$W\,{m^2}\,{K^{ - 4}}$

C

$W\,{m^{ - 2}}\,{K^{ - 4}}$

D

$W\,{m^{ - 2}}\,{K^4}$

The unit of Stefan's constant $\sigma $ is

Stefan's law is $E = \sigma ({T^4})$ 

$⇒$ $\sigma = \frac{E}{{{T^4}}}$

where,$E = $ $\frac{{{\rm{Energy}}}}{{{\rm{Area}} \times {\rm{Time}}}}$ $ = \frac{{{\rm{Watt}}}}{{{m^{\rm{2}}}}}$

$\sigma = \frac{{{\rm{Watt - }}{m^{ - 2}}}}{{{K^4}}} = Watt - {m^{ - 2}}{K^{ - 4}}$