Which of the following statements are true for the minimum deviation position of a prism?
(A). The angle of the prism is twice the angle of refraction.
(B). The refracted ray is parallel to the base of prism.
(C). The angle of incidence is equal to the angle of emergence.
(D). The angle of deviation is half the angle of a prism.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (B) and (C) only
For the minimum deviation ($\delta_\text{min}$) of a prism:
(A) Correct — At minimum deviation, the angle of incidence $i$ and angle of emergence $e$ are equal, and the refracted ray inside the prism is symmetric: $r_1 = r_2 = A/2$, where $A$ is the prism angle ✅
(B) Correct — The refracted ray inside the prism is parallel to the base of the prism ✅
(C) Correct — Angle of incidence equals angle of emergence at minimum deviation ✅
(D) Incorrect — Angle of deviation is not half the prism angle; $\delta_\text{min} = i + e - A = 2i - A$ ❌
Correct statements: (A), (B), (C)