Arrange the following media according to the critical angle with respect to air in descending order.
A. Dense flint glass
B. Water
C. Crown glass
D. Diamond
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → B, C, A, D
The critical angle \( C \) of a medium with respect to air is given by \( \sin C = 1/n \), so the larger the refractive index, the smaller the critical angle. Descending order of critical angle is ascending order of refractive index.
(B) Water: \( n = 1.33 \), \( C \approx 48.8^\circ \)
(C) Crown glass: \( n = 1.52 \), \( C \approx 41.1^\circ \)
(A) Dense flint glass: \( n = 1.65 \), \( C \approx 37.3^\circ \)
(D) Diamond: \( n = 2.42 \), \( C \approx 24.4^\circ \)
Descending order of critical angle: B, C, A, D.
Note: A similar question was also asked in CUET (UG) 2026 on 31-05-2026 (Slot 2).
NCERT (2026-27):
Total Internal Reflection – …
