Optics Question 1143
Question: Two coherent sources of intensity ratio 1 : 4 produce an interference pattern. The fringe visibility will be
[J & K CET 2004]
Options:
A) 1
B) 0.8
C) 0.4
D) 0.6
Show Answer
Answer:
Correct Answer: B
Solution:
$ \frac{I _{1}}{I _{2}}=\frac{1}{4}\Rightarrow I _{1}=k $ and $ I _{2}=4k $
$ \therefore $ Fringe visibility $ V=\frac{2\sqrt{I _{1}I _{2}}}{(I _{1}+I _{2})}=\frac{2\sqrt{k\times 4k}}{(k+4k)}=0.8 $
