The maximum kinetic energy of a photoelectron liberated from the surface of lithium with work function 2.35 eV by electromagnetic radiation whose electric component varies with time as : E=a [1+ (2 f₁ t ) ] 2 f₂ t (where a is a constant ) is (f₁=3.6 10¹⁵ ~Hz . , and f₂=1.2 10¹⁵ ~Hz and Planck's constant .h=6.6 10⁻³⁴ Js )

Step-by-step solution

Here, work function, W₀=2.35 eV and the electric component of electromagnetic radiation aligned & E=a [1+ (2 f₁ t ) ] (2 f₂ t ) & E= [a (2 f₂ t )+a (2 f₁ t ) (2 f₂ t ) ] & ( A B= 1 2 [ (A+B)- (A-B)) . & E=a (2 f₂ t )+ a 2 2 (f₁+f₂ ) t- a 2 2 (f₁-f₂ ) t aligned So, the electric component has 3 sub-components with frequencies are, f₂, (f₁+f₂ ) and (f₁-f₂ ) So, for maximum kinetic energy of photoelectron, we take photon of maximum frequency. Hence, aligned E_ & = h v_ e = 6.6 10⁻³⁴ (3.6 10¹⁵+1.2 10¹⁵ ) 1.6 10⁻¹⁹ & =19