`V_(0)` and `V_(E)` represent the velocities, m0 and mE the refractive indices of ordinary and extraordinary rays for a doubly refracting crystal. Then

Options

A. (a) `V_0geV_E`, `mu_0lemu_E` if the crystal is calcite
B. (b) `V_0leV_E`, `mu_0lemu_E` if the crystal is quartz
C. (c) `V_0leV_E`, `mu_0gemu_E` if the crystal is calcite
D. (d) `V_0geV_E`,`mu_0gemu_E` if the crystal is quartz

Answer

C

Explanation

In double refraction light rays always splits into two rays (O-ray and E-ray). O-ray has same velocity in all direction but E-ray has differenct velocity in different direction.
For calcite `mu_e`lt`mu_0`impliesv_egt`v_0`
`"For quartz" `mu_e`gt`mu_0impliesv_0`gt`v_e`