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:
An interference pattern in a Young's double-slit experiment will not be distinct if the two coherent sources are infinitesimally close. This is due to an indeterminate phase difference between the sources, preventing a stable interference pattern.
Step 2:
Reason (R) is inaccurate. Fringe width is inversely proportional to slit separation; an increase in slit separation leads to a decrease in fringe width.