Dual Nature Of Light Question 253
Question: The work function of a metallic surface is 5.01 eV. The photo-electrons are emitted when light of wavelength 2000Å falls on it. The potential difference applied to stop the fastest photo-electrons is $ [h=4.14\times {{10}^{-15}}\ eV\sec ] $ [MP PET 1991; DPMT 1999]
Options:
A) 1.2 volts
B) 2.24 volts
C) 3.6 volts
D) 4.8 volts
Show Answer
Answer:
Correct Answer: A
Solution:
Energy of incident light $ E=\frac{12375}{2000}=6.18,eV $ According to relation $ E=W_{0}+eV_{0} $
$ \Rightarrow V_{0}=\frac{(E-W_{0})}{e}=\frac{(6.18,eV-5.01,eV)}{e} $ $ =,1.17,V,\approx ,1.2,V $
BETA
