Optics (Physics) Part-II

The wavelength of red colour is highest while of violet colour is lowest. Dispersal is inverse to wavelength so red light can be seen from far away more clear. That's why the red colour is used in traffic signals.

The primary reason why the red colour is used for danger signals is that red light has the highest wavelength and scattered least by air molecules so that it can be seen from far away.

The appearance of the red colour of Sun at the sunset is due to the fact that neighbouring colours are scattered away in the path and light reaching the observer is predominantly red. That is why the Sun is seen red to us.

The primary reason why the red colour is used for danger signals is that red light has the highest wavelength and scattered least by air molecules so that it can be seen from far away.

The appearance of the red colour of Sun at the sunset is due to the fact that neighbouring colours are scattered away in the path and light reaching the observer is predominantly red. That is why the Sun is seen red to us.

The blue appearance of the sky is due to scattering of sunlight from the atmosphere. When we look at the sky, it is the scattered light which enters the eyes. Among the shorter wavelengths, the blue colour is present in a larger proportion in sunlight.

Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh's scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.

The blue appearance of the sky is due to scattering of sunlight from the atmosphere. When we look at the sky, it is the scattered light which enters the eyes. Among the shorter wavelengths, the blue colour is present in a larger proportion in sunlight.

Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh's scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.

The blue appearance of the sky is due to scattering of sunlight from the atmosphere. When we look at the sky, it is the scattered light which enters the eyes. Among the shorter wavelengths, the blue colour is present in a larger proportion in sunlight.

Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh's scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.

The blue appearance of the sky is due to scattering of sunlight from the atmosphere. When we look at the sky, it is the scattered light which enters the eyes. Among the shorter wavelengths, the blue colour is present in a larger proportion in sunlight.

Light of shorter wavelength is scattered by air molecules which because of their smaller size follow Rayleigh's scattering. Blue light is strongly scattered by the air molecules and reach the observer. This explains the blue colour of the sky.

The intensity of scattered light is inversely proportional to its wavelength and the wavelength of violet and blue is low, thus they scattered more. This is the main cause for the blue colour of the sky.

As we know that sunlight.consists of seven colours, of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore light other than red is mostly scattered away.

Most of the red light which is least scattered enters our eyes. Hence, the sun appears red. The rainbow is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. Thus, statements 1 and 3 are correct.

The intensity of scattered light is inversely proportional to its wavelength and the wavelength of violet and blue is low, thus they scattered more. This is the main cause for the blue colour of the sky.

As we know that sunlight.consists of seven colours, of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore light other than red is mostly scattered away.

Most of the red light which is least scattered enters our eyes. Hence, the sun appears red. The rainbow is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky.

The scattering of the light takes place because of the particles present in the atmosphere. At a higher altitude, the atmospheric medium is very rarer and thus, scattering of light is very low or not prominent.

Hence, the sky appears dark to the passengers flying at high altitudes. So, statements (i) and (ii) both are true, and (ii) is correct reasoning of (i).