A) \[\frac{2\pi }{\lambda }\left( {{l}_{2}}-{{l}_{1}} \right)\]
B) \[\frac{2\pi }{\lambda }\left( {{n}_{1}}{{l}_{1}}-{{n}_{2}}{{l}_{2}} \right)\]
C) \[\frac{2\pi }{\lambda }\left( {{n}_{2}}{{l}_{2}}-{{n}_{1}}{{l}_{1}} \right)\]
D) \[\frac{2\pi }{\lambda }\left( \frac{{{l}_{1}}}{{{n}_{1}}}-\frac{{{l}_{2}}}{{{n}_{2}}} \right)\]
Correct Answer: B
Solution :
Optical path for 1st ray \[={{n}_{1}}{{l}_{1}}\] Optical path for 2nd ray \[={{n}_{2}}{{l}_{2}}\] Phase difference, \[\Delta \phi =\frac{2\pi }{\lambda }\Delta x\] \[=\frac{2\pi }{\lambda }({{n}_{1}}{{l}_{1}}-{{n}_{2}}{{l}_{2}})\]You need to login to perform this action.
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