Question

Sun’s heat reaches the earth by the process of:
A. conduction
B. convection
C. radiation
D. scattering

Answer 1

Hint: Sun is an important and primary source of heat and light for the earth. Then how does this energy reach the earth? All the given options are related to the transfer of heat except scattering. Thus clearly, scattering is not the answer. But the other options are forms of heat transfer and have minor differences.

Complete step by step answer:
The sun is a hot ball of fire, which produces heat from helium which is present in the sun by the process of nuclear fusion. It is the primary source of heat and light for the earth. The heat transferred from the sun is just enough to sustain life on the earth. Additionally, Earth uses heat from the sun to perform the process of photosynthesis, which is performed by plants and other life necessary processes. The sun is also used to determine the time, as the sun rises in the morning and sets in the evening.
We know that there are three types of heat transfer, namely conduction, convection, and radiation.
In conduction, the transfer of heat is due to the collision of the molecules of the medium. Observed generally in, solids, liquids, and gases.
In convention, the transfer of heat is due to the movement of the fluids in the system. Observed generally in fluids i.e. liquids and gases.
In radiation, heat is transferred in the form of electromagnetic radiation, through the medium.
We know that space is a vacuum, and also that the electromagnetic radiations can pass through a vacuum. Hence clearly, the sun’s heat reaches the earth through the process of radiation.
Hence the answer is C. radiation.

Note:
That heat is transferred via three forms, namely conduction, convection, and radiation. These forms differ from each other due to the medium present. Also, electromagnetic radiations can pass through a vacuum. The heat transferred from the sun is just enough to sustain life on the earth.