Magnification by a lens would be greater iflight

The light from stars is refracted as it comes down into earth’s atmosphere. The air higher up in the sky is rarer and near the earth’s surface is denser. As the star light falls down the dense air bends it more and thus stars appear higher than they actually are.

Refractioncauses the bottom of a swimming pool to appear

Dispersion of light: The splitting of white light into seven colours on passing through a transparent medium is called dispersion of light.

Your imageina plane mirror is

Spectrum of white light: The band of seven colours formed when a beam of white light is passes through a glass prism is called spectrum of white light.

In 1665, Isaac Newton discovered that white light consists of seven colours. He found that if a beam of white light is passed through glass prism then it will split in to seven colours. These colours are red, orange, yellow, green, blue, indigo and violet (VIBGYOR).

It is due to refraction of light that we are able to see the sun two minutes before sunrise and two minutes after actual sunset. At the time of sunrise the sunlight is coming from less dense air to more dense air. In this case the sunlight is refracted downwards and because of this sun appears to be raised above the horizon than it actually is.

when alightbeam emergesfromwater into air, the averagelightspeed

A mirage is a result of atmospheric

When a ray of light enters the glass prism it gets deviated two times. First when it enters the glass prism and second when it comes out of the prism. This is because the refracting surfaces of the prism are not parallel to each other. Also, when the ray of light passes through the prism it bends towards its base.

Diffuse reflection occurs when the size of surface irregularities is

When the refraction of light takes place due to earth’s atmosphere it is called atmospheric refraction. So, when light ray enter the atmosphere there is air and every air layer has different temperature. These air layers have different optical densities. Cooler air layer is an optically denser medium for light rays whereas warmer air layer is optically rarer medium for light rays.

Get here current GK and GK quiz questions in English and Hindi for India, World, Sports and Competitive exam preparation. Download the Jagran Josh Current Affairs App.

The seven coloured lights recombine to form white light due to second glass prism which is placed in a reversed position.

A spectrum of seven colours of lights can be recombined to form back white light. This can be done by placing two glass prisms side by side. But, place the second glass prism in an inverted position. When white light passes through first prism it disperses the light into seven colours and when this beam of light enters the second prism which is placed in an inverted position, a white light is obtained when it comes out of the second prism.

Rainbows are not usually seen as complete circles because

Refractionoccurs whenlightpassingfromone medium to another

Rainbow is formed when it is raining at the time of sunshine. When the white sunlight falls on the raindrops and leaves them, then the white light is refracted and an arc of seven colours is formed in the sky. In this situation, tiny raindrops act as glass prism splitting the white sunlight.

When light is scattered due to particles in its path, it is called Tyndall effect. The way a beam of sunlight becomes visible when it passes through dust particles in a room, when sunlight passes through a canopy of dense forest etc., are examples of Tyndall effect.

When white sunlight falls in the atmosphere, lights with longer wavelength are not scattered by the air molecules. It is only the blue light which has shorter wavelength that is scattered most by the air molecules in the atmosphere. This is why the sky looks blue.

Stars twinkle at night because their light is refracted in the atmosphere. When the light of star enters the earth’s atmosphere it undergoes refraction due to different optical densities of the air. Therefore, stars appear bright at one moment and dim in another.

At the time of sun rise and sunset all the blue coloured light is scattered out and is away from our sight. So the light reaching us mainly at the time of sunrise and sunset is red which has longer wavelength.

The dispersion of white light happens because the angle of refraction of lights of different colours is different while passing through the transparent medium. For example, red colour deviates least and is formed at the upper part of the spectrum and violet colour is deviated maximum and is formed at the bottom of the spectrum.

In 1859, Tyndall discovered that when white light is passed through clear liquid having small suspended particles, then the blue colour of white light has shorter wavelength and is scattered more than the red colour that has longer wavelength.

A glass prism is a transparent object having two triangular ends and three rectangular sides. The refraction of light in glass prism is different from a glass slab. This is because in glass prism, the incident ray of light is not parallel to emergent ray of light.