Question

The refractive index of air, water, diamond and crown glass is 1.0003, 1.33, 2.42 and 1.52 respectively. In which medium the speed of light would be the slowest?

• A. Water
• B. Air
• C. Crown glass
• D. Diamond

Answer 1

The correct option is D Diamond

From definition of refractice index,
$\mu =\frac{c}{v}$
$v=\frac{c}{\mu }$
$v\propto \frac{1}{\mu }$

So refractive index is inversely proportional to the refractive index of a medium. Hence the speed of light is slowest in the diamond.