About $5\%$ of the power of a low light bulb is converted to visible radiation . What is the average intensity of visible radiation , at a distance of $10\;m$. Assume that the radiation is emitted isotropic-ally and neglect reflection .

Question

$\begin{array}{1 1} 4 \times 10^{-2} wm^{-2} \\ 4 \times 10^{-3} wm^{-2} \\ 4 \times 10^{-2} wm^{2} \\ 4 \times 10^{-3} wm^{2} \end{array} $