## Calculations of Electric Potential

3.3 Calculations of Electric Potential

### Learning Objectives

By the end of this section, you will be able to:

- Calculate the potential due to a point charge
- Calculate the potential of a system of multiple point charges
- Describe an electric dipole
- Define dipole moment
- Calculate the potential of a continuous charge distribution

### Electric Potential of a Point Charge

**Practice!**

Practice 3.3.1 |
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A positive charge and a negative charge are at rest with a distance of 52 cm between them. What is the electric potential at point A? |

Practice 3.3.2 |
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A positive charge and a negative charge are at rest with a distance of 52 cm between them. What is the electric potential at point B? |

Practice 3.3.3 |
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Four point charges are arranged at the corners of a square. Find the electric field E and the potential V at the center of the square. |

**Discuss!**

Reflect on this question and take notes on how you would answer it. Then we will share these thoughts together in a class discussion.

A charge of −1.0 μC is located on the *y*-axis 1.0 m from the origin at the coordinates (0,1) while a second charge of +1.0 μC is located on the *x*-axis 1.0 m from the origin at the coordinates (1,0).

Determine the value of the following quantities at the origin…

(a) the magnitude of the electric field

(b) the direction of the electric field

(c) the electric potential (assuming the potential is zero at infinite distance)

(d) the energy needed to bring a +1.0 μC charge to this position from infinitely far away