Question

$A, B$ and $C$ are three optical media of respective critical angles $C_{1}, C_{2},$ and $C_{3} .$ Total internal reflection of light can occur from $A$ to $B$ and also from $B$ to $C$ but not from $C$ to $A$. Then the correct relation between the critical angles is

• A. $C_{1} < C_{2} < C_{3}$
• B. $C_{3} > C_{1} > C_{2}$
• C. $C_{1}=C_{2}=C_{3}$
• D. $C_{1} > C_{2} > C_{3}$

Answer 1

Answer: (A)

Total internal reflection happens when light enters from a denser medium into rarer medium. Here,
$\mu_{A}>\mu_{B}>\mu_{C}$
$\Rightarrow \frac{C}{C_{1}} > \frac{C}{C_{2}} > \frac{C}{C_{3}}$
or $C_{1} < C_{2} < C_{3}$