Question

The critical angle will be largest when light goes from:

• A. water to air
• B. glass to air
• C. glass to water
• D. diamond to air

Answer 1

The correct option is D diamond to air

$\begin{array}{c}\text{Critical angle}=i_c\\ \text{we know,}\\ \sin i_c=\frac{n_2}{n_1}\end{array}$

$\begin{array}{c}{n}_2\to \text{refractive index of}\\ \text{rarer medium}\\ n_1\to \text{refractive index of denser}\\ \text{medium.}\end{array}$

$\begin{array}{c}\text{if}i\text{in increased, sin(i) is}\\ \text{increased,}\therefore \frac{n_2}{n_1}\text{is increased}\\ \text{for diamond /air transition,}\\ \frac{n_2}{n_1}\text{is}max\end{array}$