Profile
Settings
Refer your friends
Sign out
Changes in potential energy accompany the movement of a positive test charge in an electric field. As an illustration of the link between location and potential energy, a gravitational comparison was used. A positive test charge is like a mass in Earth’s gravitational field that may be moved higher by moving it in the opposite direction of the electric field. Both actions would be counterintuitive and need the involvement of a third party. The object’s potential energy would be increased as a result of this operation.
When a positive test charge moves in the direction of an electric field, it behaves as though it is being pulled downward by Earth’s gravity. Both of these changes would take place naturally, without the involvement of a human or machine to push them forward. Because of the movement, potential energy is lost. As the name suggests, potential energy is the stored energy of an object’s position with its location in a field. Learn about the electric potential and how it relates to positive test charge potential energy at different points in an electric field in Lesson 1.
Electrostatic Potential Energy In Circuits
High and low potential sites may be seen in a battery-powered electric circuit as we begin our study of electric circuits. As current flows across the circuit’s wires, it will meet varying levels of electric potential. The positive terminal of the battery creates an electric field that travels to the negative terminal via the battery’s electrochemical cells. To transport a positive test charge from the negative to the positive terminal of a cell would require effort, therefore increasing the potential energy of each Coulomb that passes along this route. A positive charge is moving against the electric field in this manner. As a result, the positive terminal is referred to as the “high potential terminal” when discussing its electrical properties. Accordingly, one may assume that the passage of the positive charge from the positive terminal to the negative terminal would be normal.
A positive test charge would travel in the direction of the electric field and would not need any effort to accomplish this task. As it goes from the positive to the negative terminals of the external circuit, the charge will lose potential energy. The phrase “low potential terminal” refers to the negative terminal. The prevalent convention that electric fields are generated by the movement of positive test charges is based on this assignment of high and low potentials to the terminals of an electrochemical cell.
In a sense, an electric circuit is nothing more than a mechanism for converting one kind of energy into another. A positive test charge is moved from the low potential terminal to the high potential terminal using chemical energy stored in the electrochemical cells of a battery-powered electric circuit. Internal circuitry converts chemical energy into electric potential energy (i.e., the battery).
An external circuit may then employ this positive test charge to do work on the light bulb, motor, or heater coils, converting its potential energy into useable forms. This is how the circuit was developed. At low energy and low voltage, the positive test charge returns to the negative terminal to restart the cycle (or circuit) all over again.
Electrostatic Potential of a Charge
Consider a system of charges made up entirely of static charges, i.e., charges that aren’t moving at all. Work done on a charge determines its potential energy in this system. To put it another way: When an object, such as a charge known as q, is placed in a certain electric field E, it feels a force proportional to the amount of its charge, equal to qE. It becomes independent of the charge if we divide the resulting work done by the amount of the charge. The electrostatic potential of a charge may be calculated using this method. The electrostatic potential of a charge is the subject of discussion in this section.
Examples of Electric Potential Energy
Estimate The electrostatic potential generated by a point charge at a distance of r
When electrostatic forces are applied to a point in an electric field, the electric potential at that point is defined as the amount of external work done in transferring a unit positive charge from infinity to that point along any path (i.e., it is path independent).
Assume that a positive charge is applied to a point P in an external electric field of a specified magnitude. Because of the presence of an electric field, the charge applied at that spot will impose an external force on the surrounding area. If a positive charge +q is present at any location r away from the positive charge, the electric potential at that point is given by:
⇒ V=Kq/r……. (1)
Where,
K – is the coulomb constant, which is equivalent to 1/4πϵ0.
The position vector is represented by the letter r.
When external work is performed in transporting a charge of one coulomb from infinity to a specific place as a result of an electric field acting against the electrostatic force, the electrostatic potential at that point is said to be one volt.
Conclusion
According to common definitions, the electrostatic potential at a given position is the product of the work done in transporting a test charge from infinity to that point and the actual charge. This definition has two things to note, even if it is not erroneous. First and foremost, only changes in electrostatic potential are significant, which implies that to define electrostatic potential, it is required to select a point that serves as the zero of potential. The point we have chosen as infinity represents a point that is extremely far away from the source of the field we are assuming and at which the field exerts no force.
