Q. For photoelectric emission from certain metal the cutoff frequency is ν. If radiation of frequency 2ν impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass)
A) √(hν/(2m))
B) √(hν/m)
C) √(2hν/m)
D) 2√(hν/m)
Explanation
[Solution from source] Work function = hν (cutoff). KEmax = h(2ν) − hν = hν = (1/2)mv², so v = √(2hν/m). Using √(hν/m) drops the factor 2 from the kinetic energy formula. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.