# Chapter 23: Electric Fields

In the previous chapter you explored Coulomb's law, the law that describes the force between charges. In this chapter, we describe what happens to the space around an electric charge; specifically, that an electric field is created. The field approach allows us to describe the force a charged particle experiences as due to the presence of the electric field created by nearby charges. Operationally, an electric field is simply a description of the force (magnitude and direction) a positively charged object would experience divided by its charge (**E** = **F**/q). In the process of representing this vector field, we will use field vectors, field lines and "test charges" (charges that only feel the force due to other charges, but do not change the external electric field).

# Table of Contents

## Illustrations

- Illustration 23.1: What is a Vector Field?
- Illustration 23.2: Electric Fields from Point Charges.
- Illustration 23.3: Field-Line Representation of Vector Fields.
- Illustration 23.4: Practical Uses of Charges and Electric Fields.

## Explorations

- Exploration 23.1: Fields and Test Charges.
- Exploration 23.2: Field Lines and Trajectories.
- Exploration 23.3: Adding Fields.

## Problems

- Problem 23.1: Find the unknown charge.
- Problem 23.2: What is the net charge?
- Problem 23.3: Identify the hidden charge distribution.
- Problem 23.4: Rank the electric fields.
- Problem 23.5: Rank the electric fields.
- Problem 23.6: Find the electric field.
- Problem 23.7: Find the electric field.
- Problem 23.8: Find the unknown charge.
- Problem 23.9: Equation for the electric field.
- Problem 23.10: Find the electric field and charge of a uniformly charged rod.