Electric Field and Electric Potential

This is Coulomb’s law we learned in Chapter 2. The Coulomb force in Eq. 3.3 can be understood as the force acting on the charge q1 under the electric field due to the other charge q2. We normally understand all electromagnetic effects by using the concept of fields. From Eqs. 3.1 and 3.2, we assume that the space is filled with a uniform dielectric. If we apply these equations to vacuum, we can put e in place of e0. 3.3 Lines of Electric Force Lines of electric force are virtual lines with directional arrows drawn in an electric field, as shown in Fig. 3.2.