Question

Two sources are called coherent if they produce waves,

$\left(i\right)$ of equal frequency

$\left(ii\right)$ having same shape of wave front

$\left(iii\right)$ having constant phase difference

$\left(iv\right)$ of equal velocity

• A. $\left(i\right)$, $\left(ii\right)$ and $\left(iv\right)$
• B. $\left(i\right)$, and $\left(iii\right)$
• C. $\left(ii\right)$ and $\left(iii\right)$
• D. $\left(i\right)$, $\left(ii\right)$, $\left(iii\right)$ and $\left(iv\right)$

Answer 1

The correct option is B $\left(i\right)$, and $\left(iii\right)$

Two sources are said to be coherent, if they produce waves having a constant phase difference and same frequency.

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