• # question_answer Sodium surface is subjected to ultraviolet and infrared radiations separately and the stopping potential of photoelectrons determined. Then the stopping potential A)  is equal in both cases B)  more when ultraviolet is used C)  more when infrared used D)  may be more or less for ultraviolet depending upon its intensity as compared to the intensity of infrared light

: For photoelectric effect, $\frac{hc}{\lambda }=\phi +$stopping potential$(eV)$ Stopping potential $(V)$is more when X is less. $\lambda$of ultraviolet$<\lambda$of infra red radiations $\therefore$stopping potential is more when ultraviolet is used.