Dual Nature Of Light Question 403
Question: For photoelectric emission from certain metal the cut-off frequency is v. If radiation of frequency 2v impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass)
Options:
A) $ \sqrt{hv/m} $
B) $ \sqrt{2hv/m} $
C) $ 2\sqrt{hv/m} $
D) $ \sqrt{hv/( 2m )} $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] From photo-electric equation, $ hv’=hv+{K_{\max }} $ ?.(i) $ 2.hv=hv+\frac{1}{2}mV_{\max }^{2}\text{ }[ \therefore v’=2v ] $
$ \Rightarrow hv=\frac{1}{2}mV_{\max }^{2}\Rightarrow {V_{\max }}=\sqrt{\frac{2hv}{m}} $
BETA
