# Electric Potential and Potential Difference

This page introduces the concepts of **electric potential** and **electric potential difference** in physics, providing essential formulas and explanations.

**Electric potential** is defined as a scalar quantity associated with points in space, used to understand an electric field's potential energy without placing a charge in the field. It is symbolized by V and measured in Joules per Coulomb.

**Vocabulary**: Electric potential - A scalar quantity representing the potential energy per unit charge at a point in an electric field.

The relationship between electric potential energy (UE) and charge (q) is given by the formula:

UE = qV

For point charges, the electric potential is calculated using the formula:

V = kQ/r

Where k is Coulomb's constant, Q is the charge, and r is the distance from the charge.

**Definition**: **Electric potential difference**, also known as voltage, is the difference in electric potential between two points in an electric field.

Key points about electric potential difference:

- It is independent of the chosen sequence
- Symbolized by ΔV and measured in volts (Joules/Coulomb)
- The change in electric potential energy is related to potential difference by ΔUE = qΔV

**Highlight**: Positive charges have positive electric potential energy (UE > 0), while negative charges have negative electric potential energy (UE < 0).

The electric potential energy at a point A (UEA) represents the work required to move a charge from a reference point (usually infinity or where U = 0) to location A.

**Example**: When calculating electric potential energy between two point charges, the formula UE = kq1q2/r is used, where q1 and q2 are the charges and r is the distance between them.

It's important to note that while you can choose the reference point for electric potential arbitrarily, the difference in potential (voltage) is what matters in calculations.

**Vocabulary**: Conservation of energy - The principle that energy cannot be created or destroyed, only converted from one form to another.

The work-energy theorem relates the work done on a charge to its change in electric potential energy. In an electric field, the work done to move a charge between two points equals the negative change in its electric potential energy.