Q. 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) $W\ m^{- 2}\ K^{4}$
Explanation
Stefan’s law is $E = \ \sigma\left( T^{4} \right)\ \Rightarrow \sigma - \frac{E}{T^{4}}$ $where,\ E = \frac{Energy}{Area\ \times Time\ \ } = \frac{Watt}{m^{2}}$ $\sigma = \frac{Watt - m^{- 2\ }}{K^{4}}\ = Watt - m^{- 2}K^{- 4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.