Question

In the case of light waves from two coherent sources `S_(1)` and `S_(2)`, there will be constructive interference at an arbitrary point P, the path difference `S_(1)P - S_(2)P` is
A. `(n+(1)/(2))lambda`
B. `n lambda`
C. `(n- (1)/(2))lambda`
D. `(lambda)/(2)`

Answer 1

Correct Answer - B
Constructive interference occurs when the path difference `(S_(1)P-S_(2)P)` is an integral multiple of `lambda`.
or `S_(1)P-S_(2)P =n lambda`
where `n = 0,1,2,3, …`