If `sigma` is Stefan's constant and b is Wien's constant, then the dimensions of length in `singma b^4` are :

Answer

4

Explanation

From `E = sigma T^4 , sigma = (E )/(T^4)`
where E is energy / sec / area and T is temperature.
`:. Sigma =(ML^2 T^(-2))/(T.L^2) xx (1)/(K^4) = [M^1 T^(-3) K^(-4)]`
From `b= lambda_m T= LK = [LK]`
Now `sigma b^4 = (M^1 T^(-3) K^(-4))(LK)^4 = [M^1 L^4 T^(-3)]`
:. Dimension of length = 4