Assuming the sun to be a black body emitting radiations with maximum intensity at λ = 0.49 μm. Calculate the heat flux at the surface of the sun.
6.93 x 107 W/m2
Wien's law gives \(T=b/\lambda_{max}=2898/0.49=5914.29\ \mathrm K\). The blackbody surface emissive power is \(E_b=\sigma T^4=5.67\times10^{-8}(5914.29)^4\approx6.94\times10^7\ \mathrm{W/m^2}\), corresponding to the listed \(6.93\times10^7\ \mathrm{W/m^2}\) option.
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