Question

Assertion: No interference pattern is detected when two coherent sources are infinitely close to each other.
Reason : The fringe width is inversely proportional to the distance between the two slits.

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

Answer 1

The correct option is A If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

When $d$ is negligibly small, fringe width. $\beta$ which is proportional to $\frac{1}{d}$ may become too large. Even a single fringe may occupy the whole screen. Hence the pattern cannot be detected.