Question

Assertion(A):- Denser medium, lesser is the velocity of light in that medium. Reason(R):- Refractive index is inversely proportional to velocity. 1 point a) Both A and R are true and R is correct explanation of the assertion. b) Both A and R are true but R is not the correct explanation of the assertion. c) A is true but R is false. d) A is false but R is true.​

Answer 1

$\large\maltese \: \underline{ \pmb{ \frak{Answer : - }}}$

• Both A and R are true and R is the correct Explanation of A.

$\large\maltese \: \underline{ \pmb{ \frak{Explanation : - }}}$

• The speed of light decreases as the medium gets optically denser.
• The partcals are closesly attached to each other in this medium
• hence, it does not allow light to pàss through easily

_________________________

$\large\maltese \: \underline{ \pmb{ \frak{Rarer\:Medium : - }}}$

• Light travels at a greater speed though this medium because the partcals are loosely held to each other.

Answer 2

Assertion(A):- Denser medium, lesser is the velocity of light in that medium.

Reason(R):- Refractive index is inversely proportional to velocity.

• Both A and R are true and R is the correct explanation of A.

But how ?

• In an optically denser medium, light rays travel at a slower velocity as compared to to an optically rarer medium.

• For example : In glass with higher refractive index (of around 2) , light rays travel at a slow velocity as compared to water which has a lower refractive index (of around 1.33).

• This is because, refractive index is indirectly proportional to the velocity of light in that particular medium.

• $\boxed{\mu\propto \dfrac{1}{v}}$

Hope It Helps