Question

. The absolute refractive index of glass and water are3/2 and 4/3 respectively. If the
speed of the light in glass is 2x10 8 m/s . Calculate the speed of light in vacuum and
water and also find the refractive index of glass with respect to water.

Answer 1

Answer:-

●Refractive index of glass=3/2=1.50

●Refractive index of water=4/3=1.33

●Speed of light in vaccum=2×10⁸m/s

$\\ \qquad\quad\sf\longmapsto \dfrac{n_g}{n_w}=\dfrac{2\times 10^8}{v_w}$

$\\ \qquad\quad\sf\longmapsto \dfrac{1.5}{1.3}=\dfrac{2\times 10^8}{v_w}$

$\\ \qquad\quad\sf\longmapsto v_w=\dfrac{1.3\times 2\times 10^8}{1.5}$

$\\ \qquad\quad\sf\longmapsto v_w=\dfrac{2.6\times 10^8}{1.5}$

$\\ \qquad\quad\pmb{\sf\longmapsto v_w=1.7\times 10^8m/s}$

Now

Refractive index of glass to water

$\\ \qquad\quad\sf\longmapsto n_{12}=\dfrac{v_w}{v_g}$

$\\ \qquad\quad\sf\longmapsto n_{12}=\dfrac{1.7\times 10^8}{2\times 10^8}$

$\\ \qquad\quad\sf\longmapsto n_{12}=\dfrac{1.7}{2}$

$\\ \qquad\quad\sf\longmapsto n_{12}=0.85$

1. Speed of light in vacuum is fixed. Its equals to 3×10⁸m/s
2. Refractive index of glass to water is 0.85