Question

A beam of light propagation in medium $A$ with index of refraction $n$ $\left(A\right)$ passes across an interface into medium $B$ with index of refraction $n\left(B\right)$. The angle of incident is greater than the angle of refraction; $v\left(A\right)$ and $v\left(B\right)$ denotes the speed of light in $A$ and $B$. Then which of the following is true

• A. $v\left(A\right)>v\left(B\right)$ and $n\left(A\right)>n\left(B\right)$
• B. $v\left(A\right)>v\left(B\right)$ and $n\left(A\right)<n\left(B\right)$
• C. $v\left(A\right)<v\left(B\right)$ and $n\left(A\right)>n\left(B\right)$
• D. $v\left(A\right)<v\left(B\right)$ and $n\left(A\right)<n\left(B\right)$

Answer 1

Answer: (B)

$v\left(A\right)>v\left(B\right)$ and $n\left(A\right)<n\left(B\right)$

According to the question,

$\because \angle i>\angle r$, it means light ray is going from rarer medium $\left(A\right)$ to a denser medium
So $v\left(A\right)>v\left(B\right)$ and $n\left(A\right)<n\left(B\right)$