Assertion (A) : No interfrence pattern is detected when two coherent sources are very closer to each other. (i.e separation almost zero)
Reason (R ) : The fringe width is inversely proportional to the distance between the two slits

Options

A. (a) If both assertion and reason are true and reason is the correct explanation of assertion.
B. (b) If both assertion and reason are true but reason is not the correct explanation of assertion.
C. (c) If assertion is true but reason is false.
D. (d) If assertion and reason both are false.

Answer

B

Explanation

When d is negligibly small, fringe width `beta` which is proportional to `1//d` may become too large. Even single fringe may occupy the whole screen. Hence the pattern cannot be detected.