MCQ
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 traveling in medium- $1$ and incident on $XY$. The lines $ef$ and $gh$ represent wavefronts of the light wave in medium- $2$ after refraction.
The phases of the light wave at $c, d, e$ and $f$ are $\phi_c,\phi_d, \phi_e$ and $\phi_f$ respectively. It is given that $\phi_c \neq \phi_f.$
- A$\phi_c$ cannot be equal to $\phi_d$
- B$\phi_d$ can be equal to $\phi_e$
- ✓$(\phi_d -\phi_f)$ is equal to $(\phi_c -\phi_e)$
- D$(\phi_d -\phi_c)$ is not equal to $(\phi_f -\phi_e)$
