Two identical photocathodes receive light of frequencies n₁ and n₂ . If the velocities of the emitted photoelectrons of mass m are V₁ and V₂ respectively, then ( h = Planck's constant)

Step-by-step solution

Using Einstein's photoelectric equation, the maximum kinetic energy of the emitted photoelectrons is given by K = hn - W , where W is the work function of the material. For the first case: 1 2 m V₁^2 = h n₁ - W For the second case: 1 2 m V₂^2 = h n₂ - W Subtracting the second equation from the first, we get: 1 2 m V₁^2 - 1 2 m V₂^2 = h n₁ - W - (h n₂ - W) 1 2 m (V₁^2 - V₂^2) = h(n₁ - n₂) V₁^2 - V₂^2 = 2h m (n₁ - n₂)