Question

Inverse square law of distance is followed by the
(A) Gravitational forces
(B) Electromagnetic forces
(C) Both (a) and (b)
(D) Neither (a) and nor (b)

Answer 1

To give the answer of this problem we must know about the Inverse square law. After that we describe the gravitational force and Electromagnetic forces, and check the relation of these forces with distance.

Complete step by step answer:
By inverse square law, any specific quantity will be in inverse relation with the square of the distance from the centre.
$X \propto \dfrac{1}{{{d^2}}}$
Here, $X$ is the specific quantity like intensity of sound, light, electric field, and $d$ is the distance from the centre.
Gravitational force: The force that attracts the object with mass is called gravitational force. This force is always of attractive nature because it always attracts the object. For example gravitational force of earth always attracts the object going away from the earth surface.
The formula of gravitational force is given by,
$F = \dfrac{{G{m_1}{m_2}}}{{{r^2}}}$
Here, $F$ is Gravitational force, $G$ is Gravitational constant, ${m_1}$ is mass of object $1$, ${m_2}$ is mass of object $2$, and $r$ is distance between centers of the masses.
So, it can be said the electric force also varies with the distance between the particles. Since Electromagnetic forces also consist of electric force, so it will also vary with distance which means it also obeys the Inverse square law.

Electromagnetic forces: The force which acts between the electrically charged particles is known as Electromagnetic forces. The electromagnetic field carries the Electromagnetic forces, and the electromagnetic field consists of both electric and magnetic fields. The electromagnetic field is responsible for several electromagnetic radiations such as light. This force is also known as Lorentz force law.

The formula of electric forces is given by,
$F = \dfrac{{k{q_1}{q_2}}}{{{r^2}}}$

Here, $F$ is electric forces, ${q_1}$, and ${q_2}$ are the charges of the particle, and $r$ is the distance between the charges.

So, it can be said the electric force also varies with the distance between the particles. Since Electromagnetic forces also consist of electric force, so it will also vary with distance which means it also obeys the Inverse square law.

Note: In this problem, the key concept is the variation of physical quantity with distance. According to the inverse square law, the intensity of the property decreases in a particular way as the distance between interacting objects increases.