Gauss's Law
Home Electrostatics Coulomb's Law Electric Field Gauss's Law Electric Potential Energy Electric Potential Capacitors Energy in Capacitors Current Electrical Power and Resistors Kirchhoff's Rules RC Circuits Magnetic Fields Moving Charges in a B-Field Magnetic Field of a Moving Charge Magnetic Field Due to a Current Ampere's Law



Physics 4, Section 2                                                        Jan 23, 2002


Electric flux Φ is the number of electric field lines cutting through a surface.


If the surface is closed, Gauss's Law gives a special case for the flux ΦE through the surface due to the net charge q inside the surface:


The point of Gauss's Law is that it uses the symmetry of special cases to simplify the calculation of electric field properties for those cases:

Point charge :

Line charge :

Sheet of charge:

where λ and σ are linear and surface charge densities, respectively.

Charges on a conductor

For a hollow conductor or a conductor with a cavity, the charge must be on the outside of the conductor. There is no charge on the inner wall of the cavity. This is easily shown using Gauss's Law.



Last modified on January 31, 2002