Question

Refractive indices of water, sulphuric acid, glass and carbon disulphide are 1.33, 1.43, 1.53 and 1.63 respectively. the light travels slowest in:

(a) sulphuric acid
(b) glass
(c) water
(d) carbon disulphide  

Answer 1

carbon disulphide

Explanation:  
Refractive index = `"speed of light in air"/"speed of light in medium "` 

Speed of light in the medium is slowest; therefore refractive index will be maximum as the speed of light in air is constant. Thus, light will travel slowest in the substance with refractive index 1.63.