Arrange the following media in the increasing order of velocity of light (λ = 500 nm) in them.
(A) Water
(B) Glass
(C) Air
(D) Diamond
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (D), (B), (A), (C)
The speed of light in a medium is \( v = c/n \), so light travels slowest in the medium with the largest refractive index.
\( \text{(D) Diamond: } n \approx 2.42 \)
\( \text{(B) Glass: } n \approx 1.5 \)
\( \text{(A) Water: } n \approx 1.33 \)
\( \text{(C) Air: } n \approx 1.0003 \)
Arranging by decreasing refractive index gives increasing speed: (D), (B), (A), (C).
NCERT (2026-27):
Total Internal Reflection – …
