Physics - Wave Optics Question with Solution | TestHub

For central maximum, path difference is zero hence phase difference for coherent sources of light will be zero. And the relation between phase difference and path difference is,$∆\varphi =\frac{2\pi }{\lambda }∆x$, where$\Delta x$is path difference and$∆\varphi$is phase difference. So due to zero path difference phase difference is also zero.