Refractive index of glass with respect to the medium is (4/3) . If the difference between velocities of light in medium and glass is 6.25 × 107 m s- 1, then the velocity of light in medium is

Question

Refractive index of glass with respect to the medium is (4/3) . If the difference between velocities of light in medium and glass is 6.25 × 107 m s- 1, then the velocity of light in medium is (A) 2.5× 108 m s- 1 (B) 0.125× 108 m s- 1 (C) 1.5× 108 m s- 1 (D) 3× 108 m s- 1

Tardigrade Admin · Accepted Answer

So, velocity of light in glass Vg=(Vm/μ ) Vm-Vg=Vm-(Vm/μ ) ∴ 6.25 × 107=Vm(1-(1/(4)3)) Vm=6.25 × 107× 4 =2.5× 108 m s- 1

Q. Refractive index of glass with respect to the medium is $\frac{4}{3}$ . If the difference between velocities of light in medium and glass is $6.25 \times 1 0^{7} m s^{- 1},$ then the velocity of light in medium is

$2.5 \times 1 0^{8} m s^{- 1}$

$0.125 \times 1 0^{8} m s^{- 1}$

$1.5 \times 1 0^{8} m s^{- 1}$

$3 \times 1 0^{8} m s^{- 1}$

So, velocity of light in glass
$V_{g} = \frac{V _{m}}{μ}$
$V_{m} - V_{g} = V_{m} - \frac{V _{m}}{μ}$
$∴ 6.25 \times 1 0^{7} = V_{m} (1 - \frac{1}{\frac{4}{3}})$
$V_{m} = 6.25 \times 1 0^{7} \times 4$
$= 2.5 \times 1 0^{8} m s^{- 1}$

Q. Refractive index of glass with respect to the medium is 34​ . If the difference between velocities of light in medium and glass is 6.25×107ms−1, then the velocity of light in medium is

2.5×108ms−1

0.125×108ms−1

1.5×108ms−1

3×108ms−1