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.

What is Refraction of Light?

Refraction of light, is the phenomenon of light in which light wave when it passes from one medium to another due to the change in the speed of the light traveling the two different media.

Applications Refraction of Light

Refraction has many applications in optics and technology. A few of the prominent applications are listed below:

• Refraction concave and convex glasses are used to correct the refractive errors of human eyes.
• Peepholes in the doors, magnifying glasses, binoculars, cameras, lenses in the projectors, etc. use the principle of refraction of light.
• A lens uses refraction to form an image of an object for various purposes, such as magnification.
• Spectacles worn by people with defective vision use the principle of refraction.
• Refraction is used in peepholes of house doors, cameras, movie projectors and telescopes.

Real-Life Applications Refraction of Light

Various applications of the refractions of light are added in the article below:

In Lenses

Refraction plays a vital role behind the functioning of lenses. There are also two lenses in our eyes that allow us to see the world around us. Many different types of lenses are used in optical devices such as cameras, spectacles, microscopes, telescopes, and projectors. Convex lenses are used in eyeglasses to correct farsightedness, which occurs when the distance between the eye’s lens and retina is too short, causing the focal point to be behind the retina. Concave lenses are used to magnify objects in telescopes and binoculars.

For example: Cameras, telescopes, microscopes, and film projectors all use lenses.

In Microscopes and Telescopes

Microscopes and telescopes both work by allowing individuals to see items that aren’t visible to the naked eye. Telescopes, on the other hand, are meant to observe distant, faint objects and have larger lens diameters, greater focal lengths and interchangeable eyepieces.

For example: In educational field, students use this device to learn new things and understand the world around them. Optical telescopes are used for astronomy and in many non-astronomical instruments, including: theodolites (including transits), spotting scopes, binoculars, camera lenses, and spyglasses.

In Prism Spectroscopy

Prism spectroscopy is a technique used in scientific research and analysis to separate light into its component wavelengths. A prism spectrometer may be used to measure the refractive index of a material if the wavelengths of the light used are known. The calibration of a prism spectrometer is carried out with known spectral lines from vapor lamps or laser light.

For example: Raindrops act as miniature prisms, bending the many colors of sunlight and dispersing them into a rainbow-like range of colors.

In Mirages

Atmospheric refraction causes mirages, where distant objects appear distorted or displaced due to variations in air density. Mirages are seen because of refraction of light.

For example: On bright sunny day when you are travelling along the roadway, the air above the roadway gets heated up and becomes optically less denser than the top layers of air, thus providing the required condition for refraction of light. In twinkling of stars, the light ray travels from star to earth in between it has to travel through vacuum and atmosphere, which contains different densities of air because of temperature and other gases present in the atmosphere providing the relevant conditions for the refraction of light.

In Fiber Optic Communication

Optical fiber has its uses in various fields like medical industry, communication, defense industries, broadcasting lighting and decorations mechanical inspections.

For example: In medical industry because of its extremely thin and flexible nature, it is used in various instruments to view internal body parts by inserting into hollow spaces in the body. In the communication system, telecommunication has major uses of optical fiber cables for transmitting and receiving purposes.

Conclusion

Refraction is another phenomenon that occurs with the ray of light. In simple terms, it is called the bending of light rays when it goes from a single transparent substance to another transparent substance. This bending results in the phenomenon of refraction of light. Hence, we are able to have objects like spectacles, glasses, prisms, rainbows, and lenses. The refraction of light occurs on the passing of light from a fast medium to a slow medium or a slow medium to fast. This always bends the ray of light away from the normal, and in the second case, to the edge of the two given mediums.

FAQs on 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.