Question

In which of the following media will a ray of light bend most, if its angle of incidence to the surface of all media is same?

• A. Water
• B. Kerosene
• C. Glycerine
• D. Mustard oil

Answer 1

The correct option is C

Glycerine

Liquid	Refractive index
Water	1.33
Kerosene	1.44
Glycerine	1.47
Mustard oil	1.46

The explanation for the correct option -

(c) Glycerine

1. For an optically denser medium the refractive index is higher than the refractive index of a rarer medium.
2. $opticaldensity\alpha \frac{1}{speedoflight}$
3. So if the refractive index is high then the speed of light in that medium will be less and the light will bend more towards the normal in that medium.
4. The refractive index of glycerine is greater than the other three given liquids. So, light bends in glycerine the most.

The explanation for the incorrect options -

(a) water

1. The refractive index of water is less than the refractive index of glycerine, so the light bends less in water than in glycerine.

(b) Kerosene

1. The refractive index of kerosene is less than the refractive index of glycerine, so the light bends less in kerosene than in glycerine.

(d) Mustard oil

1. The refractive index of mustard oil is less than the refractive index of glycerine, so the light bends less in mustard oil than in glycerine.

Hence, option (c) is correct.