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Two coherent point sources S₁ and S₂ are separated by a small distance d as shown. The fringes obtained on the screen will be

Asked in JEE Main 2013 · Fringe width and fringe position

Figure: Fringe width and fringe position
Answer: (1) concentric circles

Step-by-step solution

The sources lie on a line perpendicular to the screen.

The path difference S₁P - S₂P ≈ d cos θ depends only on the angle from this axis.

Points of equal path difference form circles centred on the foot of the axis.

The fringes are concentric circles.

Why the other options are wrong

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