The unit of Stefan's constant `sigma` is

Options

A. Watt`m^(-2)K^(-1)`
B. Watt`m^(-2)K^(-4)`
C. N`m^(-2)K^(-4)`
D. Watt`m^(-2)S^(-1)K^(-4)`

Answer

B

Explanation

Stefan's Law : `(dQ)/(dt)=sigmaAT^(4)`
`thereforesigma=((dQ)/(dt))/(AT^(4))`
`therefore` Unit of `sigma` is `J//sm^(2)K^(4)orW//m^(2)K^(4)orWm^(-2)K^(-4)`