Dual Nature Of Light Question 310
Question: Sodium and copper have work functions 2.3 $ eV $ and 4.5 $ eV $ respectively. Then the ratio of their threshold wavelengths is nearest to [AIEEE 2002]
Options:
A) 1: 2
B) 4 : 1
C) 2 : 1
D) 1 : 4
Show Answer
Answer:
Correct Answer: C
Solution:
$ W_{0}\propto \frac{1}{\lambda }\Rightarrow \frac{{\lambda_{1}}}{{\lambda_{2}}}=\frac{{{(W_{0})}{2}}}{{{(W{0})}_{1}}}=\frac{4.5}{2.3}=\frac{2}{1} $ .
BETA
