Angle of Deviation Definition: The angle of deviation is defined as the angle which is obtained from the difference between the angle of incidence and the angle of refraction created by the ray of light travelling from one medium to another that has a different refractive index.
Example of Angle of Deviation:
Question: A plane wavefront is incident at an angle of 30° on the surface of the glass. Calculate the angle of deviation if the angle of refraction is 19°.
Angle of incidence, i = 30°
Angle of refraction, r = 19°
Angle of deviation, δ = i – r = 30° – 19° = 11°