Question

Ability of crystals other than those of the isometric system to a plot a beam of ordinary light into two beams of unequal velocities.

a. birefringence
b. relief
c. colour
d. brightness
e. refraction

Answer 1

Birefringence is the ability of crystals to split an unpolarized beam of light into two beams with different velocities. The ordinary ray follows the laws of refraction, while the extraordinary ray does not.

Step-by-step explanation:

Birefringence refers to the ability of crystals to split an unpolarized beam of light into two beams with different velocities. When light passes through birefringent materials, such as the mineral calcite, it splits into an ordinary ray and an extraordinary ray. The ordinary ray behaves as expected and follows the laws of refraction, while the extraordinary ray does not follow Snell's law.

This phenomenon is due to the different indices of refraction experienced by the two rays. The ordinary ray has a specific polarization and behaves like light in isotropic materials, while the extraordinary ray has a different polarization and behaves differently based on the crystal structure.