Question:

A metal plate of area 1×10⁻⁴ m² is illuminated by a radiation of intensity 16 mW/m². The work function of the metal is 5 eV. The energy of the incident photons is 10 eV.

10¹² and 5 eV

10¹⁰ and 5 eV

10¹⁴ and 10 eV

10¹¹ and 5 eV

Maximum Kinetic Energy K.E.max = E − φ = (10 − 5) eV = 5 eV
I = nE/At
16 × 10⁻³ = (n/t) × 10 × 1.6 × 10⁻¹⁹
10⁻⁴ = 10¹²