In electrostatics, the ideas of electric field and electric potential are critical. The link between an electric field and its potential is similar to that between a gravitational field and its potential, where the potential is a feature of the field that expresses the field’s effect on an item or a body. Furthermore, the electric field exists only if and only if there is an electric potential difference. There will be no electric field if the charge is constant at all places, regardless of the electric potential. As a result, we can write “Electric field is the negative space derivative of electric potential” as the relationship between electric field and electric potential. Hence, the electric potential is per unit charge at a location in a static electric field, whereas the electric field or electric field intensity is a region of space around a charged particle or between two voltages.
Electric charge
When matter is held in an electric or magnetic field, it has an electric charge, which causes it to experience a force. An electric charge has an electric field associated with it, and a moving electric charge produces a magnetic field. The electromagnetic field is a combination of electric and magnetic fields. The electromagnetic force, which is the cornerstone of physics, is created by the interaction of the charges.
Positive and negative electric charges are transported by charge carriers’ protons and electrons, respectively. Subatomic particles or matter particles are examples of several types of charges:
Positively charged protons
Negatively charged electrons
Neutrons are neutral particles with no charge.
Electric field:
An electric field is a region of space around an electrically charged particle or object where the charge feels forced. The electric field may be examined by putting another charge into it, which exists everywhere in space.
For practical purposes, the electric field can be approximated as 0 if the charges are far enough away. Electric fields are represented by arrows pointing toward or away from charges as a vector quantity. The lines must either point outwards, from a positive charge, or inside, toward a negative charge.
The magnitude of the electric field is computed using the formula:
E=F/q
where E denotes the strength of the electric field, F denotes the electric force, and q denotes the test charge.
Electric potential
The electric potential is defined as the work done by conservative forces to move a unit positive charge in the opposite direction of an electric field, or the electric potential difference is defined as the work done by conservative forces to move a unit positive charge, and it is symbolised by V.
The electric potential at a position is also equal to the quotient of the potential energy of each charged particle at that location divided by its charge. J C-1is the name of the unit. As a result, the electric potential is a guess at how much energy is stored per unit of charge.
The electric potential and charge are closely related in terms of units. They have the same C-1 factor, although force and energy vary only by a factor of distance, with energy being the product of force and distance.
Coulomb’s law
Coulomb’s Law describes the force that occurs between two-point charges. The term “point charge” in physics refers to the fact that linearly charged objects are small in comparison to the distance between them. As a result, we regard them as point charges since calculating their attraction or repulsion force is simple.
In general, the statement has two charges, q1 and q2. The letter ‘F’ stands for the attraction/repulsion force between the charges, while the letter ‘r’ stands for the distance between them. Coulomb’s law is then mathematically represented as-
F is proportional to the product of the charges in contact’s magnitudes, i.e., F α q1q2
F is inversely proportional to the square of the contact distance between the two charges, i.e., F α*1/r².
When proportionality is removed, a constant k is introduced;
F=k*q1q2/r²
Here, k is the proportionality constant, which equals 1/4πξ0, ξ0 is the permittivity of free space. The value of k has been determined to be 9×109 Nm²/C².
Relation between electric field and electric potential
The gravitational field and the gravitational potential possess the same relationship as the electric field and electric potential. The electric field is the negative slope of the electric potential, according to the basic relationship between electric field and potential.
Mathematically the equation will be:
E=-dV/dx
Here, E is the electric field, V is the electric potential and dx is the length of the path.
According to this relation we can conclude that electric field and electric potential are directly proportional. Therefore, as the electric field increases, the electric potential also increases.
Conclusion
The electric field always points in the direction of the steepest potential drop (maximum). The change in the strength of electric potential per unit movement normal to the equipotential surface at the location determines the size of the electric field.