Question

The refractive index of glass is $\frac{3}{2}$. Velocity of light in glass would be

• A. $3\times {10}^{8}m{s}^{-1}$
• B. $2\times {10}^{8}m{s}^{-1}$
• C. ${10}^{8}m{s}^{-1}$
• D. $1.33\times {10}^{8}m{s}^{-1}$

Answer 1

The correct option is B $2\times {10}^{8}m{s}^{-1}$

$Fromn=\frac{c}{v},v=\frac{c}{n}=\frac{3\times {10}^8}{\left(\frac{3}{2}\right)}=2\times {10}^{8}m/s$
where n is the refractive index, c is the velocity of light, v is the velocity of light in glass