The number of photons `(lambda = 6630 Å)` that strije per second on a totoally reflecting screen (as shown in figure), so that a force of `1N` is exerted on the screen, is approximentely).

Options

A. `10^(23)`
B. `10^(27)`
C. `10^(25)`
D. `10^(26)`

Answer

B

Explanation

`F = (dp)/(dt) rArr F = ((2P sin theta)/(Deltat))`
`rArr F = 2nsintheta` [`n =` number of photon]
`rArr 1N = 2[n] (h)/(lambda) sin 30^(@) rArr n = 10^(27)`