Dual Nature Of Light Question 385
Question: The threshold wavelength of the tungsten is 2300 If ultraviolet light of wavelength $ 1800\overset{o}{\mathop{A}}, $ is incident on it, then the maximum kinetic energy of photoelectrons would be about
Options:
A) 1.49eV
B) 2.2eV
C) 3.0eV
D) 5.0eV
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ {K_{\max }}=hv-hv_{0}=hc( \frac{1}{\lambda }-\frac{1}{{\lambda_{0}}} ) $ Use $ hc=1.24\times {{10}^{-6}}( eV )m $ $ hc=1.24\times {{10}^{-6}}( \frac{10^{8}}{18}-\frac{10^{8}}{23} ) $ $ =\frac{1.24\times 100\times ( 23-18 )}{18\times 23}=1.49eV $
BETA
