Question

The unit of Stefan's constant is

• A. Wm^-2K^-1
• B. WmK^-4
• C. Wm^-2K^-4
• D. Nm^-2K^-4

Answer 1

The correct option is C

Wm^-2K^-4

The explanation for the correct answer:-

Option (C)

1. According to Stefan's law, the energy radiated per second or power radiated is given by
   $P=\sigma A{T}^4$, P is the power radiated by the body
2. $\sigma =\frac{P}{A{T}^4}$, σ is Stefan's constant. A is the surface area of the body, T is its Temperature
3. $\sigma =\frac{Watt}{m^2{K}^4}$=$W{m}^{-2}{K}^{-4}$, W stands for Watt., m for Metre, K for Kelvin.
4. Therefore, the unit of Stefan’s constant is $W{m}^{-2}{K}^{-4}$.

Hence option C is the correct option.