Question

What are the field forces in Physics?

Answer 1

Hint: To answer our question, we will first understand what does a field mean. In Physics, the field is a region (of attraction or repulsion) inside which each point is affected by a force due to which the field is created. The effect of this force is measured by field lines. The region with more field lines has stronger force and the region with lesser field lines has a weaker force in the region.

Complete answer:
A field force is described with the help of a vector quantity which determines the magnitude and direction of this force in the field at any point. All the field forces are non-contact in nature. There are two fundamental field forces in nature, the Gravitational force and the Electromagnetic force. Let us look at them in details as follows:
(2) Gravitational force: it is one of the four fundamental forces in nature and exists between any two bodies in the universe that have mass. Gravitational force is only attractive in nature. The force on a test mass ‘m’ due to the gravitational field of a mass ‘M’ is given by:
$\Rightarrow \overrightarrow{F}=G{\displaystyle \frac{Mm}{r^2}}\hat{n}$
Where,
‘r’ is the distance between the masses and ‘$\hat{n}$’ is the unit vector along the direction of force.
(2) Electric force: it is one of the four fundamental forces in nature and is one of the ‘electromagnetic’ forces. It exists between any two bodies in the universe that have charge. Electric force is both attracting and repelling in nature. The force on a test charge ‘q’ due to the electric field of a charge ‘Q’ is given by:
$\Rightarrow \overrightarrow{F}=k{\displaystyle \frac{Qq}{r^2}}\hat{n}$
Where,
‘r’ is the distance between the masses and ‘$\hat{n}$’ is the unit vector along the direction of force.
Hence, the two field forces in Physics are Gravitational force and electric force.

Note:
Magnetic force might also be considered as a field force depending upon the nature of the force. Magnetic field produces a force which affects moving charges within its area of influence but does not affect stationary charges. This is why it cannot be completely said to be a field force.