Question

If refractive index of a medium is $1.5$, then velocity of light in that medium will be:

• A. $ 10\times 10^{8} $
• B. $ 2\times 10^{8} $
• C. $ 3\times 10^{8} $
• D. $ 4\times 10^{8} $

Answer 1

Answer: (B)

Refractive index $n=\frac{c}{v}$
$v=\frac{c}{n}=\frac{3 \times 10^{8}}{1.5}$
$=2 \times 10^{8} m / s$