# How To Find Critical Angle?

## What is the critical angle formula?

The critical angle can be calculated by taking the inverse-sine of the ratio of the indices of refraction.

The ratio of nr/ni is a value less than 1.0.

In fact, for the equation to even give a correct answer, the ratio of nr/ni must be less than 1.0.

## How do you find the critical angle of water?

Critical Angle Formula. Critical Angle can be described as the angle of incidence that offers an angle of refraction of 90 degrees. Remember that the critical angle is defined as an angle of incidence value. The critical angle will be 48-6-degrees for water-air boundaries and 61.0-degrees for crown glass-water boundary

## How do you find critical angle from refractive index?

Refractive Index and Critical Angle –

## What is called critical angle?

The angle at which the incident ray after refraction grazes (i.e; makes 90° with the normal) is called the critical angle. Any ray incident at an angle greater than the critical angle undergoes total internal reflection.