calculate the number of photons emitted per secound by a 10W sodium vapour lamp.Assume that 60% of the consumed energy is converted into light. Wavelength of sodium light = 590nm?

let λ be wavelength. light energy=6J/sec,let number of photons be 'n' , nhc/λ=6, solve for'n' 

Dear Asheesh Tyagi,

E = 6 J/s

We know that ,

λ = 590nm

E = nhc/λ

n = 6λ/hc

n= 1.78 * 10¹⁹ photons 

Hope this helped you immensely...

All the Very Best & Good Luck to you ..

Regards,

AskIITians Expert,

Godfrey Classic Prince

IIT-Madras

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