Question

Two coherent point sources $S_1$ and $S_2$ are separated by a small distance $d$ as shown. The fringes obtained on the screen will be-

• A. Points
• B. Straight lines
• C. Semi-circles
• D. Concentric circles

Answer 1

The correct option is D Concentric circles

The fringes will be concentric circle due to constant path difference.
These will be concentric circles as the path difference at all points on the screen at an equal distance from the centre of the screen remains same.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(D\right)$ is the correct answer.