Question

Assertion: Two point coherent sources of light S₁ and S₂ are placed on a line as shown. P and Q are two points on that fine. If at point P maximum intensity is observed then maximum intensity should also be observed at Q.

Reason : In the figure of assertion the distance |S₁P - S₂P| is equal to distance |S₂Q - S₁Q|.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

The correct option is (b).

Explanation:

If maximum intensity is observed at P then for maximum intensity to be also observed at Q, S₁ and S₂ must have phase difference of 2 mπ (where m is an integer).