Question

The refractive indices of glass and water with respect to air are $\frac{3}{2}$ and $\frac{4}{3}$ respectively. Then the refractive index of glass with respect to water is

• A. $\frac{8}{9}$
• B. $\frac{9}{8}$
• C. $\frac{7}{6}$
• D. 2
• E. 0.5

Answer 1

Answer: (B)

Refractive index of glass with respect to air
${}_a{\mu }_g=\frac{3}{2}$
Refractive index of water with respect to air
${}_a{\mu }_w=\frac{4}{3}$
Refractive index of glass with respect to water
${}_w{\mu }_g=\frac{{}_a{\mu }_g}{{}_a{\mu }_w}$
${\therefore }_w{\mu }_g=\frac{\left(\frac{3}{2}\right)}{\left(\frac{4}{3}\right)}=\frac{9}{8}$