Question

If $C$ is the critical angle and $n$ is the refractive index of a denser medium with respect to the rarer medium, $sinC\times n$ is .

• A. $0$
• B. $1$
• C. $\infty$

Answer 1

The correct option is B $1$

Snell's law states that,
$\frac{sin\left(i\right)}{sin\left(r\right)}=\frac{{\mu }_2}{{\mu }_1}$ where $i$ and $r$ are the angle of incident and the angle of refracted ray respectively.
For the above case, light should enter from denser to rarer medium.
$\frac{sin\left(i\right)}{sin\left(r\right)}=\frac{{\mu }_r}{{\mu }_d}$
$\frac{sin\left(C\right)}{sin\left(90\right)}=\frac{1}{{\mu }_d/{\mu }_r}$
$\frac{sin\left(C\right)}{1}=\frac{1}{n}$
$sin\left(c\right)\times n=1$