Capacitors and Inductors
A capacitor is an electrical device that is used to store electrical energy. Next to the resistor, the capacitor is the most commonly encountered component in electrical circuits. For example, capacitors are used to smooth rectified AC outputs, they are used in telecommunication equipment—such as radio receivers—for tuning to the required frequency, they are used in time delay circuits, in electrical filters, in oscillator circuits, and in magnetic resonance imaging (MRI) in medical body scanners, to name but a few practical applications.
Figure 4.1 represents two parallel metal plates, A and B, charged to different potentials. If an electron that ...