Dual Nature Of Light Question 402
Question: The surface of a metal is illuminated with the light of 400 nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is: $ ( hc=1240eV.nm ) $
Options:
A) 1.41 eV
B) 1.51 eV
C) 1.68 eV
D) 3.09 eV
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ \lambda =400nm,hc=1240eV.nm,K.E.=1.68eV $ We know that, $ \frac{hc}{\lambda }-W=K.E.\Rightarrow W=\frac{hc}{\lambda }-K.E $
$ \Rightarrow W=\frac{1240}{400}-1.68=3.1-1.68=1.42eV $
BETA
