Electric field strength

Definition

Electric field strength is a measure of the force experienced by a unit positive charge placed in an electric field. It is represented by the symbol $E$ and is measured in volts per meter (V/m).

5 Must Know Facts For Your Next Test

1. Electric field strength can be calculated using the formula $E = \frac{F}{q}$, where $F$ is the force on the charge and $q$ is the magnitude of the charge.
2. The direction of the electric field is defined as the direction of the force that would act on a positive test charge placed in the field.
3. Electric field lines point away from positive charges and toward negative charges.
4. Uniform electric fields have constant magnitude and direction, typically created between two parallel plates with opposite charges.
5. The principle of superposition states that the net electric field caused by multiple charges is the vector sum of fields created by each individual charge.

Review Questions

• What is the formula to calculate electric field strength?
• In which direction do electric field lines point relative to positive and negative charges?
• How does superposition apply to calculating net electric field from multiple sources?

Related terms

Coulomb's Law: Describes the force between two point charges; given by $F = k \frac{|q_1 q_2|}{r^2}$ where $k$ is Coulomb's constant, $q_1$ and $q_2$ are the magnitudes of charges, and $r$ is their separation distance.

Electric Potential: The work done per unit charge in bringing a test charge from infinity to a point in space; measured in volts (V).

Gauss's Law: $\text{States that } \oint \mathbf{E} \cdot d\mathbf{A} = \frac{Q_{\text{enc}}}{\epsilon_0}$, relating electric flux through a closed surface to the enclosed charge.