Question

(i) In the explanation of photo electric effect, we asssume one photon of frequency ν collides with an electron and transfers its energy. This leads to the equation for the maximum energy E_max of the emitted electron as

E_max = hν – φ₀

where φ₀ is the work function of the metal. If an electron absorbs 2 photons (each of frequency ν ) what will be the maximum energy for the emitted electron? 

(ii) Why is this fact (two photon absorption) not taken into consideration in our discussion of the stopping potential?

Answer 1

(i) E_max = 2hv – ϕ

(ii) The probability of absorbing 2 photons by the same electron is very low. Hence such emissions will be negligible.