A metal was irradiated by light of frequency 3.2 X 10^15 s^-1. The photoelectron produced has its KR, 2 times the KE of photoelectron which was produced when the same metal was irradiated with a light of frequency 2.0 X 10^15 s^-1. What is its work function?

K.E = hv -W

w is work fucnction in ev

h is planks constant = 4.14x10^-15 ev-sec

K.E₁ = hv₁ -W  and K.E₂ = hv₂ -W

(hv₁ -W) = 2.(hv₂ -W )

W = h(2v₂ -  v₁₎

     ₌ 4.14x10^-15 * (4 - 3.2)*x10¹⁵

     Work function = 3.312 eV

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