Physics - Wave Optics Question with Solution | TestHub

Paragraph:The figure shows a surface $XY$ separating two transparent media, medium-1 and medium-2. The lines $ab$ and $cd$ represent wavefronts of a light wave travelling in medium-1 and incident on $XY$. The lines ef and $gh$ represent wavefronts of the light wave in medium-2 after refraction.
Question:The phases of the light wave at $c,d,e$ and $f$ are ${\varphi }_c,{\varphi }_d,{\varphi }_e$ and ${\varphi }_f$, respectively. It is given that ${\varphi }_c\ne {\varphi }_f$.