A 600 W mercury lamp emits monochromatic radiation of wavelength 313.3 nm. How many photons are emitted from the lamp per second ? (h = 6.626 xx 10^(-34) Js, velocity of light = 3xx 10^(8) ms^(-1))

A 600 W mercury lamp emits monochromatic radiation of wavelength 313.3

1.	A 600 W mercury lamp emits monochromatic radiation of wavelength 313.3 nm. How many photons are emitted from the lamp per second ? (h = 6.626 xx 10^(-34) Js, velocity of light = 3xx 10^(8) ms^(-1))
Answer» `1 xx 10^(19)` `1 xx 10^(20)` `1 xx 10^(21)` `1 xx 10^(23)` SOLUTION :`600 W = 600 J s^(-1) (1 W = 1 Js^(-1))` i.e., Energy EMITTED per SEC = 600 J Energy of one photon, `E = hv = h (C)/(lamda)` `= (6.626 xx 10^(-34) Js xx 3 xx 10^(8) MS^(-1))/(313.3 xx 10^(-9) m)` `= 6.344 xx 10^(-19) J` `:.` Photons emitted per sec `= (600)/(6.344 xx 10^(-19))` `~= 1 xx 10^(21)`