Optics Question 1108
Question: In Young’s double slit experiment using sodium light $ (l=5898{AA}) $ , 92 fringes are seen. If given colour $ (l=5461{AA}) $ is used, how many fringes will be seen
[CPMT 1989; RPET 1996; JIPMER 2001, 02]
Options:
A) 62
B) 67
C) 85
D) 99
Show Answer
Answer:
Correct Answer: D
Solution:
$ (n _{1}{\lambda _{1}}=n _{2}{\lambda _{2}}) $
$ \frac{n _{1}}{n _{2}}=\frac{{\lambda _{2}}}{{\lambda _{1}}}\Rightarrow \frac{n _{1}}{92}=\frac{5898}{5461}\Rightarrow n _{1}=99 $
