What will be the acceleration due to gravity at the centre of the Earth?
(A) Zero.
(B) Infinity.
(C) $9.8$
(D) $98$

Hint: One of the forces of nature is the force of gravity. The force of gravity according to Sir Isaac Newton is the pull of that is the attraction of any two objects with mass. In case of gravity it is the attraction between the earth and the object that is placed on it. The force of gravity always pulls the object with mass together and does not push them apart.

Complete step by step solution
The acceleration that is attained by the object because of the influence of gravitational force of the earth is called the acceleration on account of gravity. The S.I. unit of acceleration on account of gravity if $m{s^2}$. It is a vector quantity since it has direction as well as the magnitude. We represent it using its symbol $g$ .

When we move to the Earth’s centre the mass of the body is distributed equally in all directions. The gravitational pull from all sides of the Earth becomes stronger and stronger as we move to the core of the Earth. Since the shape of the Earth is a perfect sphere, the gravity at the centre of the Earth is almost the same on all sides. This can only mean that the gravitational pull of an object from one side cancels the other side of the pull. That is the gravity cancels each other from all sides simultaneously. Since the Earth is not a perfect sphere, we may experience a slight gravity pull of very minimum scale to none. Due to minimum to none gravity the acceleration due to gravity will be none.

Therefore, at the Earth centre the acceleration due to Gravity is Zero.

Hence, the option (A) is the correct answer.

Note: According to some of the studies of the interior of the Earth, that is the core’s structure can be studied with the help of the Seismic activities that are happening due to the earthquakes. The seismic waves pass through the entire Earth. The seismic waves carry the vital information about the internal structure of the Earth’s core. These waves bend when they pass through the Earth, like a light ray that passes through a prism.