A point source of \( 100 \, \mathrm{W} \) emits light with \( 5\% \) efficiency. At a distance of \( 5 \, \mathrm{m} \) from the source, the intensity produced by the electric field component is:
$\frac{1}{10\pi} \frac{W}{m^2}$
$\frac{1}{2\pi} \frac{W}{m^2}$
$\frac{1}{20\pi} \frac{W}{m^2}$
$\frac{1}{40\pi} \frac{W}{m^2}$