Graph shows variation of stopping potential with frequency of incident radiation on a metal plate. The value of Planck's constant is [ e = charge on photoelectron]

Step-by-step solution

The photoelectric effect follows Einstein's photoelectric equation : h = + K_ max , where h is Planck's constant, is the frequency of incident radiation, is the work function, and K_ max is the maximum kinetic energy. Since K_ max = eV_s where e is the electronic charge, substitution gives: h = + eV_s . Solving for V_s yields the linear relation: V_s = h e - e . This corresponds to a straight line with slope m = h/e . From the graph, the slope is calculated using two points: m = (V₂ - V₁)/( ₂ - ₁) . Equating the ex