1.3 Electric Field

1.3 Electric Field

The electric field at a point is the force experienced per unit positive test charge:

$$\vec{E} = \frac{\vec{F}}{q_0} = \frac{1}{4\pi\varepsilon_0} \cdot \frac{q}{r^2}\,\hat{r}$$

Electric Field Lines

• Start from positive charges, end at negative charges.
• Never cross each other.
• Density of lines represents the field strength.
• Tangent at any point gives the direction of $\vec{E}$.