Refraction of Light

Define Refraction of Light

The phenomenon of the change in the direction of propagation of light as it passes from one transparent medium to another is called refraction of light.

State an Example of Refraction of Light.

An example of refraction is the rainbow. The light rays bend as they enter water drops in the atmosphere forming a rainbow.

What are Laws of Refraction of Light?

Following are laws of refraction of light:

• Incident ray, the normal to the interface and the refracted ray of two transparent media at the point of incidence, all lie in the same plane.
• Ratio of sine of angle of incidence to the sine of angle of refraction is a constant, for the light of a given color and for the given pair of media. This law is also known as Snell’s law of refraction.

If ‘i’ is the angle of incidence and ‘r’ is the angle of refraction, then

sin i/sin r = Constant

What are Factors affecting Refraction of Light?

Following factors affect the refraction of light:

• Density of Medium: The density of the medium affects the refraction of the light. When the density of the medium is low, it does not refract the light much. The denser medium refracts light as it slows down the velocity of light which causes refraction.
• Temperature and Pressure: The effect of temperature and pressure can be understood by the differences in the refractive index of air at higher and lower altitudes. At high altitudes, where the temperature and pressure are low the density of air is low and therefore it refracts the light much less than at low altitudes where the pressure is high and the temperature is moderate.
• Wavelength of Light: The light comprises of 7 major colors. These colours are having different wavelengths. When light passes through the medium, the color which has low wavelength refracts less and the color which has a higher wavelength refracts more.

What is Cause of Refraction of Light?

Refraction of light occurs because light travels with different speeds in different media.

What is Refractive Index of a Medium?

Refractive index of a medium (for light of a given wavelength) is defined as the ratio of the speed of light in vacuum to the speed of light in that medium.

Light seems to travel along straight-line paths in a transparent medium. What happens when light enters from one transparent medium to another? Does it still move along a straight-line path or change its direction? The answer to this in this case light changes its direction and this property of light is called refraction. There are various uses of refraction in real life.

In this article, we will learn about, Refraction of Light definition, its application and others in detail.