Question

When petrol drops from a vehicle fall over rain water on road surface, colours are seen because of:
A. Dispersion of light.
B. Interference of light.
C. Scattering of light.
D. Absorption of light.

Answer 1

Hint: Petrol is a fuel that is used to run the engines of various vehicles and generators. When a drop of petrol falls in the water, it will not dissolve in it like salt or sugar because the petrol and fuels like petrol have fat that never allows the petrol to dissolve in the water, instead it will form a layer in the water and reflect a number of colours.

Complete answer:
When the petrol droplets from a vehicle fall over rain water then the petrol will not dissolve in it, instead a layer is formed over the water then if we allow the light to fall the layer, we can observe the number of colours in it. It is due to the light interference on the upper and the lower parts of the layer formed.
In the mixture of the rain water and the petrol droplets, the light interferes and is responsible for the reflection of different colours, so it is called as the interference of the light in the water and petrol mixture.
Due to the interference, we can observe a number of colours like red, green, orange, blue, etc. on it.

So, the correct answer is “Option B”. Therefore, the correct answer is interference of the light

Note:
It is clear that the colours can be observed only when there is light, the light is the responsible for the reflection of the colours. The absence of light on the layer will not show any colours on it.