Electrostatic Potential and Capacitance Test - 10

Aluminium electrolytic capacitors have the Aluminium foil anode (positive terminal) which is etched and covered with a layer of Aluminium Oxide which acts as a dielectric. The whole assembly is covered using a paper separator soaked in electrolyte such as, Borax or Glycol and covered by Aluminium foil which acts as cathode (negative electrode)

A submarine cable consists of an inner conductor which carries power. This conductor is covered by an insulator, which acts as a dielectric. The dielectric material is covered by a metal coating called shield, which is connected to ground. The cable acts as a cylindrical capacitor, with the conductor acting as the inner cylinder, and the metal shield as the outer cylinder which is connected to earth.

Atomic dipoles in a dielectric experience a torque when placed in an external electric field. As a result of this torque, they align themselves in the direction of the electric field, since this is the position of least potential energy. This phenomenon in which the atomic dipoles align themselves in the diorection of the electric field is called dielectric polarization.

When an uncharged capacitor is connected to a battery, charges flow from the poles of the battery to the plates of the capacitor and this process continues till the potential across the capacitor attains the potential difference of the battery. The current flows in the circuit till the time the capacitor is charged and then it ceases.