Question

The source of energy of the sun is-
A. Coal
B. Petroleum
C. Gravitational force
D. Nuclear reactions

Answer 1

Hint: The Sun at the core of the Solar System is considered a major star. It is a special and ideal sphere composed of hot plasma, with internal convective motion which gives birth to a magnetic field through a process called the dynamo process. So far it is the most powerful and essential source of life-energy on Earth.

Complete Step-by-Step solution:
Its diameter is calculated to be about 1.39 million kilometres (864,000 miles), or 109 times that of the calculated diameter of the Earth, and its mass is around 330,000 times that of the mass of the Earth. It is responsible for about 99.86% of the complete mass of the Solar System. Around 75% of the Sun’s mass is made up of hydrogen; the rest of the left mass is mostly helium, with a lot of smaller quantities of heavier elements which includes oxygen, carbon, neon, and iron.
When hydrogen fusion has collapsed at its core to the point that the Sun is no longer in hydrostatic equilibrium, the centre will slowly become a red giant as its outer layers expand. The Sun is supposed to turn out to be massive enough to dive into Mercury and Venus' present orbits, and make Earth inhabitable — but not for another five billion years. Right after this incident, it will shed its outer layers and become a dense kind of cooling star called a white dwarf, and no longer generate energy by the process of fusion, yet at the same time glow and radiate heat from its previous fusion.
Thus, it can be said that the source of the Sun's energy is due to nuclear reactions.

Hence, option D is the correct option.

Note: As of now when measured, the Sun consistently fuses about 600 million tons of hydrogen into helium, thus continuously turning more than 4 million tons of matter into energy. This energy, which can take somewhere in the range of 10,000 and 170,000 years to escape from its core, is the source of the Sun's light and heat.