Question

At sunrise the sun looks reddish due to:
A. Dispersion
B. Reflection
C. Scattering
D. Reflection

Answer 1

It is based on the phenomenon in which the light rays coming from the sun gets deviated from its straight-line path after striking the various particles suspended in the atmosphere. The degree of deviation depends upon the wavelength of the light.

Complete step by step answer:
In the given question, we are told that at sunrise, the sun appears to be more reddish.
We are asked to find the reason for this phenomenon.
To answer this question, We must have observed that during the sunrise in the early morning the sun appears to be reddish. This may be due to the fact that all the different colours are associated with different wavelengths. Since, the wavelengths are associated with the energies of that corresponding colour. The equation which gives the relation between the energy and the wavelength is given below:
$E = \dfrac{{hc}}{\lambda }$
Where,
$E$ indicates the energy of that particular colour.
$h$ indicates Planck’s constant.
$c$ indicates speed of light.
$\lambda$ indicates the wavelength of the light of that particular colour.
It indicates that energy is inversely proportional to the wavelength of the light, which means higher is the energy, lower is its wavelength, or vice-versa.
The light spectrum is commonly known as VIBGYOR, which gives the sequence of decreasing order of energies of the spectrum. It indicates that blue light has the highest energy while the red light has the lowest energy. Then we can say that the wavelength of the blue light is the shortest while the longest wavelength is for the red light.
At sunrise we see the sun reddish in colour, which is due to scattering of light. This is the phenomenon in which the light rays get deviated from the straight in which it was moving, after striking an obstacle like dust particles, atmospheric water vapour molecules, etc.
Since, the red light has the longest wavelength, it can travel a longer distance while the blue light gets scattered off due to its shorter wavelength.

The correct option is C.

Note: It is important to note that red light has lowest energy while blue light has the highest. So, when you place a pan full of water over a blue flame and another identical pan over a red flame, then the pan placed over a blue flame boils faster, because blue light has more energy.