Optics Question 1036
Question: Two coherent sources of intensities, I1 and I2 produce an interference pattern. The maximum intensity in the interference pattern will be
[UPSEAT 2001; MP PET 2001]
Options:
A) I1 + I2
B) $ I _{1}^{2}+I _{2}^{2} $
C) (I1 + I2)2
D) $ {{(\sqrt{I _{1}}+\sqrt{I _{2}})}^{2}} $
Show Answer
Answer:
Correct Answer: D
Solution:
Resultant intensity $ I _{R}=I _{1}+I _{2}+2\sqrt{I _{1}I _{2}}\cos \varphi $
For maximum $ I _{R}, $
$ \varphi =0^{o} $
Therefore $ I _{R}=I _{1}+I _{2}+2\sqrt{I _{1}I _{2}}={{( \sqrt{I _{1}}+\sqrt{I _{2}} )}^{2}} $
