A 600 W mercury lamp emits monochromatic radiation of wave length 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)`)

Options

A. `1xx10^(19)`
B. `1xx10^(20)`
C. `1xx10^(21)`
D. `1xx10^(23)`

Answer

C

Explanation

Power=`("Energy")/("time")`
`600=(nhc)/(lamdaxx1sec)`
`600=(nxx6.626xx10^(-34)xx3xx10^(8))/(331.3xx10^(-9))`
`n=1xx10^(21)`.