Consider following statements for refraction of light through prism, when angle of deviation is minimum.
(A) The refracted ray inside prism becomes parallel to the base.
(B) Larger angle prisms provide smaller angle of minimum deviation.
(C) Angle of incidence and angle of emergence becomes equal.
(D) There are always two sets of angle of incidence for which deviation will be same except at minimum deviation setting.
(E) Angle of refraction becomes double of prism angle.
Choose the correct answer from the options given below.
(A) The refracted ray inside prism becomes parallel to the base.
(B) Larger angle prisms provide smaller angle of minimum deviation.
(C) Angle of incidence and angle of emergence becomes equal.
(D) There are always two sets of angle of incidence for which deviation will be same except at minimum deviation setting.
(E) Angle of refraction becomes double of prism angle.
Choose the correct answer from the options given below.
- (A)A, C and D Only✓ Correct
- (B)B, C and D Only
- (C)A, B and E Only
- (D)B, D and E Only
Answer: (A)
Solution
At minimum deviation the ray passes symmetrically through the prism. The refracted ray inside the prism then runs parallel to the base, so the first statement holds. Symmetry also makes the angle of incidence equal to the angle of emergence, so the third statement holds. For any deviation larger than the minimum there are two angles of incidence giving the same deviation, and only at the minimum is that angle unique, so the fourth statement holds. A larger refracting angle gives a larger minimum deviation, so the second statement is false, and at minimum deviation each internal refraction angle is half the prism angle, , not double it, so the fifth statement is false. The correct statements are the first, the third and the fourth.
JEE Main · 2025 · 03 Apr 2025 · Shift 1 · Single correct option