Q. The distance travelled by light in glass (refractive index = 1.5) in a nanosecond will be
A) $45\ cm$
B) $40\ cm$
C) $30\ cm$
D) $20\ cm$
Explanation
(d) Distance $= v \times t = \frac{c}{\mu} \times t = \frac{3 \times 10^{8}}{1.5} \times 10^{- 9}$
$= 0.2\ m = 20\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.