Light from a firefly can expose photographic film but the ra

Light from a firefly can expose photographic film, but the radiation from an FM station broadcasting 50000 W at 180 MHz cannot. Explain why this is so.

Solution

The frequency of light from firefly is nearly of the order of 5.88*10^14 Hz which is very large comapred to 180 MHz.

To expose the photographic film minimum frequency known as threshold frequency is required and it seems that the frequency of 180MHz is so small that itt cannot expose the photographic film.