# How do you get negative potential?

Answered by Antonio Sutton

To understand how negative potential can be obtained, let’s start by revisiting the concept of potential energy. In physics, the electric potential energy of a charged particle is the amount of work done to bring that charge from infinity to a specific point in an electric field. It is measured in joules (J).

The electric potential at a point in an electric field is the electric potential energy per unit charge at that point. It is measured in volts (V). The electric potential at a reference point is usually defined as zero, and the potential at any other point is measured relative to this reference point.

Now, let’s consider a scenario where we have two charged particles. One is located at the reference point, and the other is at a measured point. The potential energy of a charge at the reference point is typically defined as zero. This means that no work is required to bring the charge from infinity to the reference point, as there is no electric potential energy associated with it.

If the potential energy of the charge at the reference point is more than the charge at the measured point, it implies that more work is required to bring the charge from infinity to the reference point compared to bringing it to the measured point. In other words, the measured point has a lower potential energy compared to the reference point.

Since potential difference is a measure of the difference in electric potential between two points, it is calculated by subtracting the potential at the reference point from the potential at the measured point. In this scenario, if the potential at the reference point is zero and the potential at the measured point is negative (lower potential energy), then the potential difference between these two points will be negative.

To illustrate this concept, let’s consider the example of a positive charge and a negative charge. The positive charge creates an electric field, and the negative charge is placed in this field. The potential at the reference point is defined as zero, and the potential at the measured point (closer to the positive charge) is negative.

As the negative charge moves closer to the positive charge, its potential energy decreases, resulting in a lower potential at the measured point. This negative potential indicates that the negative charge has lost potential energy as it moved closer to the positive charge.

Negative potential can be obtained when the potential energy of a charge at a measured point is lower than the potential energy at the reference point. This indicates that the charge at the measured point has lost potential energy relative to the reference point, resulting in a negative potential difference between these two points.