What is power (in watt) of a light source emitting `3.125 xx 10^(18)` photons per second, while the wavelength of light is `620 nm` ? (use `hc = 12400 eVÅ`)

Answer

`1`

Explanation

Let the power be `x` wants.
No. of photons emitted per second `xx` Energy of `1` photon `=` Total energy
`:. 3.125 xx 10^(18) xx (12400)/(6200) = (x)/(1.6 xx 10^(-19)`
`:. x = 1`