Question

Speed of light in vacuum is 3 x 10'm/s and the R.l. of medium with respect to vacuum is

1.4 Find the speed of light in that medium.​

Answer 1

GiveN :-

• Speed of light in vacuum is 3×10⁸ m/s.
• The RI of medium wrt vacuum is 1.4 .

To FinD :-

• The speed of light in that medium.

SolutioN :-

Given that Speed of light in vacuum is 3 x 10'm/s and the R.l. of medium with respect to vacuum is 1.4 and we need to find the speed of light in that medium .

We know that the Refractive index is the ratio of speed of light in vacuum to the speed of light in a medium . So ,

★ According to Refractive Index :-

$\sf:\implies \pink{ \mu =\dfrac{ v_{(light \ in \ vaccum)}}{v_{(light \ in \ a \ med^m )}} }\\\\\sf:\implies 1.4 = \dfrac{3\times 10^8 m/s}{v }\\\\\sf:\implies v = \dfrac{3\times 10^8 m/s}{1.4}\\\\\sf:\implies\underset{\blue{\sf Required\ speed }}{\underbrace{ \boxed{\pink{\frak{ v_{(in \ a \ med^m)} = 2.14 \times 10^8 m/s }}}}}$