The electric flux \(\Phi_E\) through a loop, calculated using Equation 16-6, is defined in precisely the same manner as the magnetic flux \(\Phi_B\) through a loop. The quantity \(\epsilon_0(\Delta{\Phi_E/\Delta{t})}\) has units of amperes and is called the displacement current. Experiment confirms Equation 22-8: A circulating magnetic field can be produced by an electric current, by a changing electric field, or a combination.