Optics Question 1069
Question: In a certain double slit experimental arrangement interference fringes of width 1.0 mm each are observed when light of wavelength 5000 Å is used. Keeping the set up unaltered, if the source is replaced by another source of wavelength 6000 Å, the fringe width will be
[CPMT 1988]
Options:
A) 0.5 mm
B) 1.0 mm
C) 1.2 mm
D) 1.5 mm
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{{\beta _{1}}}{{\beta _{2}}}=\frac{{\lambda _{1}}}{{\lambda _{2}}} $ or $ \frac{1.0}{{\beta _{2}}}=\frac{5000}{6000} $ or $ {\beta _{2}}=\frac{6000}{5000}=1.2\ mm $ .