The unit of Stefan's constant $$\sigma$$ is
Correct option is C. $$W\, m^{-2}K^{-4}$$
Stefan's law is $$E=\sigma (T^4)$$
$$\Rightarrow \sigma =\dfrac{E}{T^4}$$
where,$$E=\dfrac{Energy}{Area \times Time}=\dfrac{Watt}{m^2}$$
$$\sigma =\dfrac{Watt-m^2}{k^4}=Watt-m^{-2}k^{-4}$$