Question

The refractive index of glass for light going from air to glass is .

The refractive index for light going from glass to air will be:

(a) `1/3`

(b) `4/5`
(c) `4/6` 
(d) `5/2`

Answer 1

 4/6

Explanation: 
Refractive index of material 2 with respect to material 1 is given by:  

₁n_{2 =`"speed of  light in medium 1"/"speed of light in medium 2"`} 

_{By the same argument, refractive index of medium 1 with respect to medium 2 is given by:}  

_{2n1 = `"speed of light in medium 2"/"speed of lighht in medium 1"`=1/1n2}   

_{1n2  is `3/2` therefore,  2n1 will be 1/ `3/2`} 

_{Therefore, refractive index of light going from glass to air will be 4/6.}