Potential of Line Charge

The potential of a line of charge can be found by superposing the point charge potentials of infinitesmal charge elements. It is an example of a continuous charge distribution.

Potential for Ring of Charge

The potential of a ring of charge can be found by superposing the point charge potentials of infinitesmal charge elements. It is an example of a continuous charge distribution. The ring potential can then be used as a charge element to calculatethe potential of a charged disc.

Since the potential is a scalarquantity, and since each element of the ring is the same distancer from the point P, the potential is simply given by If the charge is characterized by anarea density and the ring by anincremental width dR', then:

In this form it could be used as a charge element for the determining of the potential of a disc of charge.

Potential for Disc of Charge

The potential of a disc of charge can be found by superposing the point charge potentials of infinitesmal charge elements. It is an example of a continuous charge distribution. The evaluation of the potential can be facilitated by summing the potentials of charged rings. The integral overthe charged disc takes the form: