12. ultraviolet light of energy 3.5 ev and intensity 100 w/m2 is directed at a potassium surface (work function of potassium is 2.2 ev). find the maximum kineti

12. Ultraviolet light of energy 3.5 eV and intensity 100 W/m2 is directed at a potassium surface (Work function of potassium is 2.2 eV). Find the maximum kinetic energy of the photo electrons. 12. (A) 1.0eV (B) 1.20 eV (C) 1.30 eV (D) 1.23 eV 28 4 for