Question

Two coherent sources can produce a resultant wave of -

Amplitude, angular frequency, wave number and phase of the two waves remain constant.

• A. constant phase
• B. varying phase
• C. Both
• D. None of these

Answer 1

The correct option is A constant phase

Let us suppose the two waves are,

$y_1=A_1\sin (\omega t-k{x}_1)$, and
$y_2=A_2\sin (\omega t-k{x}_2+\theta )$,

The phase $\left(\alpha \right)$ of the resultant wave is given by,

$\tan \alpha =\frac{A_2\sin \theta }{A_1+A_2\cos \theta }$

As the amplitude and phase (so phase difference) of the two waves remain constant, the phase of the resultant wave is also constant.

Hence, option $\left(A\right)$ is the correct answer.