Question

Assertion (A): In a Young's double-slit experiment, interference pattern is not observed when two coherent sources are infinitely close to each other. % Reason (R) Reason (R): The fringe width is proportional to the separation between the two sources.

• A. If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
• B. If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).
• C. If Assertion (A) is true but Reason (R) is false.
• D. If both Assertion (A) and Reason (R) are false.

Hint:

For clear interference patterns in Young's experiment, the slits should be separated by a finite distance, and the sources should remain coherent.

Answer 1

The Correct Option is C

Step 1:
In a Young's double-slit experiment, the interference pattern will not form clearly if the two coherent sources are infinitely close to each other. This is because the phase difference between the two sources becomes indeterminate, leading to no stable interference pattern.
Step 2:
The reason (R) is incorrect because the fringe width is actually inversely proportional to the separation between the slits, not directly proportional. As the separation between the slits increases, the fringe width decreases.