Q. Light propagates 2cm distance in glass of refractive index 1.5 in time$t_{0}$. In the same time$t_{0}$, light propagates a distance of 2.25 cm in a medium. The refractive index of the medium is
A) 4/3
B) 3/2
C) 8/3
D) None of these
Explanation
(a) For a given time, optical path remain constant
$\therefore\ \ \mu_{1}x_{1} = \mu_{2}x_{2}$
Or $1.5 \times 2 = \mu_{2} \times 2.25$
$\therefore\ \ \ \ \ \mu_{2} = \frac{1.5 \times 2}{2.25} = \frac{2}{1.5} = \frac{20}{15} = \frac{4}{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.