Question

Choose the correct option:-

Assertion (A): Higher the refractive index of a medium, lesser the velocity of the light in that medium.
Reason (R): Refractive index is inversely proportional to velocity.

• A. Both A and R are true, and R is not the correct explanation of A.
• B. Both A and R are true, and R is the correct explanation of A.
• C. A is true, but R is false.
• D. A is false, but R is true.

Answer 1

The correct option is B Both A and R are true, and R is the correct explanation of A.

The refractive index of a medium:
$n_m=\frac{Speedoflight}{Speedoflightinthemedium}=\frac{c}{v}$

$\Rightarrow$Refractive index of a medium is inversely proportional to velocity of light in that medium.
Therefore, higher the refractive index of a medium, lesser will be the velocity of the light in that medium.