Q. $V_{o}$ and $V_{E}$ represent the velocities, $\mu_{o}$ and $\mu_{E}$ the refractive indices of ordinary and extraordinary rays for a doubly refracting crystal. Then
A) $V_{o} \geq V_{E},\mu_{o} \leq \mu_{E}$ if the crystal is calcite
B) $V_{o} \leq V_{E},\mu_{o} \leq \mu_{E}$ if the crystal is quartz
C) $V_{o} \leq V_{E},\mu_{o} \geq \mu_{E}$ if the crystal is calcite
D) $V_{o} \geq V_{E},\mu_{o} \geq \mu_{E}$ if the crystal is quartz
Explanation
(c) In double refraction light rays always splits into two rays ($O$-ray & $E$-ray). $O$-ray has same velocity in all direction but $E$-ray has different velocity in different direction
For calcite $\mu_{e} < \mu_{0} \Rightarrow v_{e} > v_{0}$
For quartz $\mu_{e} > \mu_{0} \Rightarrow v_{0} > v_{e}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.