Test: Waves - NEET MCQ

y1= A1 sin wt
y2= A2 cos (wt + f)
Now, y2 = A2 sin (wt + f + pi/2)
So, phase difference = f + pi/2
Path Difference = (λ/2pi)(f + pi/2)
Hence B.

Two sources are said to be coherent if there always exists a constant phase difference between the waves emitted by these sources. But when the sources are coherent, then the resultant intensity of light at a point will remain constant and so interference fringes will remain stationary.

The necessary condition for phenomenon of interference to occur are:
1. There should be two coherent sources.
2. The frequency and amplitude of both the waves should be same.
3. The propagation of waves should be simultaneously and in same direction.
These are the conditions, no explanation.

Interference occurs for both transverse and longitudinal waves.
Interference does not indicate whether light is transverse or longitudinal since interference occurs for both types of waves.