The work function of metal ' A ' and ' B ' are in the ratio 1: 2 . If light of frequency ' f ' and ' 2 f ' is incident on surface ' A ' and ' B ' respectively, then the ratio of kinetic energies of emitted photo electrons is

Step-by-step solution

aligned & For A , E _ A _ = h v- _ A & For B , E _ B _ = h (2 v)- _ B & E _ A _ E _ B _ = h v- _ A 2 ~h v- _ B & As _ A _ B = 1 2 _ B =2 _ A aligned aligned E _ A _ E _ B _ & = h v- _ A _ A 2 ~h v- _ B _ A = h v _ A -1 2 h v _ A -2 & = hv - _ A _ A _ A 2 ( ~h v- _ A ) = 1 2 aligned