Question

Ultraviolet light is incident on metals P, Q and R, having work functions 8 eV, 2 eV and 4 eV respectively,

1. Which metal has lowest threshold frequency for photoelectric effect?
2. For which metal is the value of E_max minimum?
   (Note: E_max is maximum kinetic energy of the emitted photoelectrons.)

Answer 1

1. The metal (Q) with a work function of 2 eV has the lowest threshold frequency since E₀ = hv₀.
2. Since, E_max = E - E₀, the metal (P) having work function of 8 eV will have minimum E_max.