22.4 Applications of Gauss's Law
Gauss's law is valid for any distribution of charges and
for any closed surface.
Gauss's law can be applied in two ways:
1) if we know the charge distribution and if it has
enough symmetry to evaluate the integral in Gauss's
law, we can find the electric field
2) if we know the electric field, we can use Gauss's law
to find the charge distribution
1
, Example: Charge distribution on a conductor
When excess charge is placed on a solid conductor and
is at rest, it resides entirely on the surface, not in the
interior of the material.
- In electrostatic cases E
at every point in the
interior of the conductor
is zero
- If E were not zero, the
charges would move
2
Gauss's law is valid for any distribution of charges and
for any closed surface.
Gauss's law can be applied in two ways:
1) if we know the charge distribution and if it has
enough symmetry to evaluate the integral in Gauss's
law, we can find the electric field
2) if we know the electric field, we can use Gauss's law
to find the charge distribution
1
, Example: Charge distribution on a conductor
When excess charge is placed on a solid conductor and
is at rest, it resides entirely on the surface, not in the
interior of the material.
- In electrostatic cases E
at every point in the
interior of the conductor
is zero
- If E were not zero, the
charges would move
2
