Q. When monochromatic radiation of intensity I falls on a metal surface, the number of photoelectron and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2I, the number of emitted electrons and their maximum kinetic energy are respectively
A) N and 2T
B) 2N and T
C) 2N and 2T
D) N and T
Explanation
[Solution from source] Doubling intensity doubles the number of photons per second, so the number of photoelectrons doubles to 2N. The maximum kinetic energy depends only on frequency and work function (hν − φ), so it stays T. Doubling the kinetic energy would need a change in frequency, not intensity. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.