Question

Which of the following statements is/are correct regarding refractive index?

• A. It is the measure of the degree of bending of a light ray on change of medium.
• B. It gives a measure of the speed of a light ray in a medium.
• C. A higher refractive index means a higher speed of light in that medium.
• D. An optically rarer medium has lower refractive index.

Answer 1

Answer: (A), (B), (D)

The correct options are
A It is the measure of the degree of bending of a light ray on change of medium.
B It gives a measure of the speed of a light ray in a medium.
D An optically rarer medium has lower refractive index.

Refractive index of a medium 2 with respect to a medium 1 is defined as:
${\mu }_{2,1}=\frac{v_1}{v_2}$
where-
$v_1:$ Speed of light in the first medium
$v_2:$ Speed of light in the second medium

Also, higher refractive index implies that light ray is more inclined towards the normal. In other words, angle of refraction is lesser for higher refractive index.