Question

१
र ४
7. If the velocity of light of light in a medium is 2x10⁵ msec‐¹then the refractive index of that medium is:
(B) 1.0 (c) 2.4
(a) 1.5
(d) None of these
गदे मागम में नाश क थे। 2x10⁵ m Sec‐¹ है, तो उस माध्यम का
अपईनन जय होगा।
(ii) 1.0
(a) 1.5
(d) इनमें से कोई नहीं
(b) 2.4
​

Answer 1

It is given that the speed of light in a transparent medium is 2 x 10^5 m / s.

From the properties of light, we know that the refractive index of a medium is the ratio of speed of light in vaccum to the speed of light the given medium.

We know that speed of light in vaccum is 3 x 10^8 m / s.

Therefore,

= > Refractive of the transparent medium = ( speed of light in vaccum ) / ( speed of light in that medium )

= > Refractive of the transparent medium = ( 3 x 10^8 m / s ) / ( 2 x 10^5 m / s )

= > Refractive of the transparent medium = 3 x 10^( 8 - 5 ) / 2

= > Refractive of the transparent medium = 3 x 10^3 / 2

= > Refractive index of the transparent medium = 1.5 x 10^3.

Hence the refractive of the transparent medium is 1.5 x 10^3.

Thus, the required correct option is ( d ) i.e. None of these. $\:$