- Electric Potential Definition: Electric potential is defined as the work needed to bring a unit positive charge from infinity to a point in an electric field.
- Potential Difference: The potential difference between two points is the work needed to move a unit positive charge from one point to another.
- Units of Electric Potential: The unit of electric potential is the volt, defined as one joule of work per one coulomb of charge.
- Electric Potential of Charged Bodies: A charged body can do work by attracting or repelling other charges, which is its electric potential.
- Electric Potential Calculation: Electric potential at a point due to a charge can be calculated using the work done to move a unit positive charge.
Similarly, the potential difference between two points is defined as the work required to be done for bringing a unit positive charge from one point to other point.
When a body is charged, it can attract an oppositely charged body or repel a similarly charged body. This ability to do work is defined as the electrical potential of the body.
If two electrically charged bodies are connected by a conductor, electrons flow from the lower potential body to the higher potential body, creating a current. This flow depends on the potential difference between the bodies and the resistance of the conductor.
Electric potential of a body is its charged condition, determining whether it will receive or give up electric charge to another body.
Electric potential is graded as an electrical level, and the difference between two levels causes current to flow. This level is measured from a reference zero level, with the earth’s potential taken as zero. Electric potential above this is positive, and below is negative.
The unit of electric potential is volt. To bring a unit charge from one point to another, if one joule work is done, then the potential difference between the points is said to be one volt. So, we can say,
If one point has electric potential 5 volt, then we can say to bring one coulomb charge from infinity to that point, 5 joule work has to be done.
If one point has potential 5 volt and another point has potential 8 volt, then 8 – 5 or 3 joules work to be done to move one coulomb from first point to second.
Potential at a Point due to Point Charge
Let us take a positive charge + Q in the space. Let us imagine a point at a distance x from the said charge + Q. Now we place a unit positive charge at that point. As per Coulomb’s law, the unit positive charge will experience a force,
Now, let us move this unit positive charge, by a small distance dx towards charge Q.
During this movement the work done against the field is,
So, total work to be done for bringing the positive unit charge from infinity to distance x, is given by,
As per definition, this is the electric potential of the point due to charge + Q. So, we can write,
Potential Difference between Two Points
Let us consider two points at distance d1meter and d2 meter from a charge +Q.
We can express the electric potential at the point d1 meter away from +Q, as,
We can express the electric potential at the point d2 meter away from +Q, as,
Thus, the potential difference between these two points is
