# Define the Term Refractive Index of a Medium. What Do You Understand by the Statement 'The Refractive Index of Glass is 1.5 for White Light'? - Physics

Short Note

Define the term refractive index of a medium. What do you understand by the statement 'the refractive index of glass is 1.5 for white light'?

#### Solution

When light travels from one medium (air) to another medium (glass), it bends towards the normal. The extent of bending of light depends upon the speed of light (v2) in the second medium, compared to the speed of light (v1) in the first medium. The refractive index of the second medium w.r.t. the first medium (n21) is given by
n21 = Speed of light (v1) in first medium / speed of light (v2) in second medium
The refractive index of glass is typically around 1.5, meaning that light in glass travels at
c / 1.5 = 200,000 km/s. A low value of refractive index also indicates a large critical angle at the glass-air interface.

Concept: Refraction of Light - Refraction of Light Through a Glass Block and a Triangular Prism
Is there an error in this question or solution?

#### APPEARS IN

Frank ICSE Class 10 Physics Part 2
Chapter 2 Light
Exercise 2.1 | Q 16 | Page 88