Question

Which is the position of minimum deviation in prism?

• A. When the angle of incidence is such that the refracted ray inside the prism is parallel to the base of the prism.
• B. When the angle of incidence is such that the refracted ray inside the prism reflects back from the base of the prism
• C. When the angle of incidence is such that the refracted ray inside the prism reflects back from the base of the prism
• D. When the angle of incidence is such that the refracted ray inside the prism is at 45 degrees to the base of the prism.

Answer 1

The correct option is A

When the angle of incidence is such that the refracted ray inside the prism is parallel to the base of the prism.

When the angle of incidence is such that the refracted ray inside the prism is parallel to the base of the prism this is prism’s position of minimum deviation.There is only one angle of incidence, for which the angle of deviation is minimum.