Question

The refractive index of the glass is 3/2 band of water is 4/3.What would be the refractive index of water wrt glass? Does light travel faster in glass than in water? Calculate the speed of light in water

Answer 1

Dear Student,
$$\begin{gathered} Refractiveindexofwater,{\mu }_w=\frac{4}{3} \\ Refractiveindexofglass,{\mu }_g=\frac{3}{2} \\ Refractiveindexofwaterw.r.t.glass=\left(\frac{4}{3}\right)/\left(\frac{3}{2}\right)=\frac{8}{9} \end{gathered}$$

Since the refractive index of water is less than that of air, Light travel faster in water than in glass.

$$\begin{gathered} Refractiveindexofwater=\frac{c}{v_g} \\ \frac{4}{3}=\frac{c}{v_g} \\ {v}_g=\frac{3c}{4}=\frac{3\times 3\times {10}^8}{4}=\frac{9}{4}\times {10}^{8}m/s \end{gathered}$$

Regards