Question

Figure shown plane waves refracted from air to water using Huygen's principle $a,b,c,d,e$ are lengths on the diagram. The refractive index of water with respect to air is equal to

• A. $\frac{a}{e}$
• B. $\frac{b}{e}$
• C. $\frac{b}{d}$
• D. $\frac{d}{b}$

Answer 1

The correct option is C $\frac{b}{d}$

From Snell's law,
${\mu }_a\sin i={\mu }_w\sin r$
$\frac{b}{c}={\mu }_{wa}\frac{d}{c}$
$\Rightarrow {\mu }_{wa}=\frac{b}{d}$