Question

If the refractive index of glass is 1.5, velocity of light in glass is

• A. $1.5\times {10}^{8}m{s}^{-1}$
• B. $2\times {10}^{8}m{s}^{-1}$
• C. $3\times {10}^{8}m{s}^{-1}$
• D. $4.5\times {10}^{8}m{s}^{-1}$

Answer 1

Answer: (B)

$2\times {10}^{8}m{s}^{-1}$

Given, refractive index of glass

${\mu }_g=1.5$

We know,

$\mu =\frac{Speedoflightinvacuum}{Speedoflightinmedium}=\frac{c}{v}$

$\Rightarrow v=\frac{c}{{\mu }_g}$

$\Rightarrow v=\frac{3\times {10}^8}{1.5}=2\times {10}^{8}m{s}^{-1}$

$\Rightarrow v=2\times {10}^{8}m{s}^{-1}$

Hence, the correct answer is OPTION B.