Question

If the speed of light in a medium is is 2 x 10⁸ m/s. What is the the absolute refractive index of the medium? (Velocity of light in vacuum is 3 x 10⁸m/s) *​

Answer 1

Answer:

Refractive index = Velocity of light in vacuum/ Velocity of light in a medium

= 3*10^8 m/s / 2*10^8 m/s

= 1.5 Ans.

The medium may be a glass.

Answer 2

Given:-⠀⠀⠀⠀

$\sf Speed \: of \: light \: in\: a \: medium = 2 \times 10^8 m/s$⠀⠀

$\sf Speed \: of \: light \: in\: a \: vacuum = 3 \times 10^8 m/s$

To find :-

$\sf Refractive \: index = \mu = ??$

⠀⠀⠀

Solution :-

$\begin{gathered}\bigstar\:{\underline{\sf We \:know \:that \::}}\\ \end{gathered}$

The refractive index of a medium is defined as the ratio of the speed of light in vacuum to the speed of light in that medium .

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

$\star\:{\boxed{\sf{\red{\mu = \dfrac{speed_{(vacuum)}} { speed_{(Medium) }}}}}}$⠀⠀⠀

$\begin{gathered} :\implies\sf \mu = \dfrac{3\times 10^8}{ 2 \times 10^8} \\ \end{gathered}$⠀⠀⠀⠀

$\begin{gathered} :\implies\sf \mu = \dfrac{3}{2} \\ \end{gathered}$⠀⠀⠀⠀

$\begin{gathered} : \implies \sf \mu = 1.5 \\ \end{gathered}$⠀⠀⠀⠀

$\begin{gathered}: \implies{\underline{\boxed{\rm{\blue{Refractive \: index = \: 1.5}}}}}\;\bigstar\\ \end{gathered}$⠀⠀⠀⠀

$\therefore\:{\underline{\sf{Refractive \; index \; of \;the \: medium \; is \; \bf{ 1.5}.}}}$

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