Light described at a place by the equation `epsilon = (100 V/m)[sin(5 xx 10^(15)s^(-1))t + sin (8 xx 10^(15)s^(-1))t]` falls on a metal surface having work function 2eV. Calculate the maximum kinetic energy of the photo electrons.

Options

A. 5.27 eV
B. 1.71 eV
C. 3.27 eV
D. 0.854 eV

Answer

C

Explanation

For longer frequency
`v= omega/(2pi) = (8 xx 10^(15))/(2pi)s^(-1)`
`K.E._("max") = hv - phi`
`K.E_("max") =(6.6 xx 10^(-34) xx 8 xx 10^(15))/(1.6 xx 10^(-19) xx 2 xx 3.14)-2`
`=5.27 -2 = 3.27 eV`