How is it related to the refractive index of the medium ?

Explanation

To find the relationship between the critical angle (Ic) and the refractive index (µ) of a medium, we can follow these steps:

### Step 1: Understand the Critical Angle
The critical angle is defined as the angle of incidence above which total internal reflection occurs when light travels from a denser medium to a less dense medium.

### Step 2: Define the Refractive Index
The refractive index (µ) of a medium is defined as the ratio of the speed of light in vacuum (c) to the speed of light in the medium (v):
\[ \mu = \frac{c}{v} \]
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