Question

The unit of Stefan's constant is

• A. $Wm^{-2}k^{-1}$
• B. $Wmk^{-4}$
• C. $Wm^{-2}k^{-4}$
• D. $Nm^{-2}k^{4}$

Answer 1

Answer: (C)

According to Stefan's law, the energy radiated per second or power radiated is given by
$P=\sigma A T^{4} $
$\sigma=\frac{P}{A T^{4}}$
Therefore, unit of $\sigma=\frac{ W }{ m ^{2} K ^{4}}= Wm ^{-2} K ^{-4}$