Presence of Voltage and Charges
Charge on Surface: A voltage difference requires the presence of charges, leading to the formation of an electric field. In static electric circuits with potential differences, charges are present on the surfaces of conductors, generating an electric field with a direction perpendicular to the surface. The field lines terminate on surface charges, indicating that these charges do not spread out evenly.
Direction of Electric Field
The electric field touching a conductive surface in a static situation has a direction perpendicular to the surface, preventing any component of the field along the surface. The E-field lines either terminate or originate on surface charges, and these charges cannot move due to the inability of electrons to jump off the surface.
Uniformity of Charge Distributions
Charge distributions on a conductive surface are not necessarily uniform in a static situation. Despite non-uniform charge distribution, the potential along the surface remains constant, meaning the work required to bring a test charge to the conductive surface is the same for all points on the surface.
The paragraph also introduces Figure 1, illustrating the field pattern for two conductors over a conductive plane. Conductor 1 is at a potential of 1 V, and conductor 2 is at a potential of 2 V. The work required to move a unit charge from the conductive plane to the surface of the first conductor is 1 V, and the field lines show the direction from positive to negative charges. The conductive plane is considered a reference conductor at 0 V, requiring 2 V of work to move the unit charge back to the conductive plane. The concept of a conducting plane as a ground or reference plane is emphasized, highlighting areas with positive and negative charge accumulations on its surface. The reference surface is defined as zero potential, and the scenario is related to the context of circuit connections, signals, and reference conductors in practical applications.