Dual Nature Of Light Question 91
Question: The maximum velocity of an electron emitted by light of wavelength $ \lambda $ incident on the surface of a metal of work function $ \varphi , $ is [MP PMT/PET 1998, MP PMT 2003]
Options:
A) $ {{[ \frac{2(hc+\lambda \varphi )}{m\lambda } ]}^{1/2}} $
B) $ \frac{2(hc-\lambda \varphi )}{m} $
C) $ {{[ \frac{2(hc-\lambda \varphi )}{m\lambda } ]}^{1/2}} $
D) $ {{[ \frac{2(h\lambda -\varphi )}{m} ]}^{1/2}} $ Where h = Planck’s constant, m = mass of electron and c = speed of light.
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Answer:
Correct Answer: C
Solution:
According to Einstein?s photoelectric equation $ \frac{hc}{\lambda }=\varphi +\frac{1}{2}mv^{2}\Rightarrow v={{[ \frac{2(hc-\lambda \varphi )}{m\lambda } ]}^{1/2}} $
BETA
