Ts Eamcet
Electromagnetic Waves
TS EAMCET 2022 (Online) 19th July Morning Shift
MCQ+1 / -02022
About $20 \%$ of the power of a 100 W bulb is converted to visible radiation. Assuming that the radiation is emitted isotropically and neglecting reflection, the average intensity of visible radiation at a distance of 5 m is $\frac{\alpha}{25 \pi} \mathrm{~W} / \mathrm{m}^2$. The value of $\alpha$ is