Dual Nature Of Light Question 315
Question: When radiation is incident on a photoelectron emitter, the stopping potential is found to be 9 volts. If $ e/m $ for the electron is $ 1.8\times 10^{11},C,k{{g}^{-1}} $ the maximum velocity of the ejected electrons is [Kerala (Engg.) 2002]
Options:
A) $ 6\times 10^{5},m{{s}^{-1}} $
B) $ 8\times 10^{5},m{{s}^{-1}} $
C) $ 1.8\times 10^{6},m{{s}^{-1}} $
D) $ 1.8\times 10^{5},m{{s}^{-1}} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{1}{2}mv_{\max }^{2}=eV_{0}\Rightarrow {v_{\max }}=\sqrt{2( \frac{e}{m} )V_{0}} $ $ =\sqrt{2\times 1.8\times 10^{11}\times 9}=1.8\times 10^{6}m/s. $
BETA
