What is minimum deviation in a prism? State the conditions for minimum deviation.
The condition when the angle of deviation between the incident ray and emergent ray is the least for a ray passing through a prism is considered as minimum deviation in a prism.
In the condition of minimum deviation,
angle of incidence (i) = angle of emergence (e)
angle of refraction at face 1 (r1) = angle of refraction at face 2 (r2)
angle of deviation = angle of minimum deviation