Four light waves are represented by
(i) `y=a_1sin omegat`
(ii) `y=a_2 sin (omega t+varphi)`
(iii) `y=a_1sin 2 Omega t`
(iv) `y=a_2sin 2(omegat+varphi)`
Interference fringes may be observed due to superposition of

Options

A. (a) `y=a_1 sin omega t`
B. (b) `y=a_2 sin (omega t+varphi)`
C. (c) `y=a_1sin 2 omega t`
D. (d) `y=a_2 sin 2(omegat+varphi)`

Answer

A

Explanation

These waves are of same frequencies and they are coherent.