- #1
jamesrb
- 11
- 0
For an upcoming lab I will be mapping out the equipotential lines in an electric field with an isolated conductor in it. The conductor is a hollow cylinder. I have attached a crude paint drawing of the apparatus. The lab asks some qualitative questions that I would like to knock out before hand.
1. What can you say about the electric field within the hollow cylinder? Justify your answer in terms of the relationship between the electric field and the electric potential.
2. If the potential difference between the parallel plates would be increased what would happen with the surface potential on the cylinder? What about the electric field within the cylinder?
3. What can you conclude about the potential and electrical fields inside hollow or solid uncharged conductive objects?
Perhaps this may help but not really needed:
[tex]V_{f}-V_{i}=-\int_{i}^{f}\overrightarrow{E}\cdot d\overrightarrow{s}[/tex]
1. I believe the electric field in a conductor is zero. Any excess charge is distributed to the surface. If an isolated conductor is placed in an external electric field all points of the conductor still come to a single potential regardless of whether the conductor has an excess charge. The free conduction electrons distribute themselves on the surface in such way that the electric field they produce at interior points cancels the external electric field.
2. Would the surface potential on the cylinder increase but the electric field in the cylinder stays zero? Stack more an more charge on the surface all you want, you aren't going to increase the electric field inside the cylinder. It will just distribute itself on the surface more and more.
3. The electric field inside is always zero? Any electrical potential is in regard to the surface of the conductors?
Here is my fantastic paint drawing if someone really needs it to picture the apparatus:
Homework Statement
1. What can you say about the electric field within the hollow cylinder? Justify your answer in terms of the relationship between the electric field and the electric potential.
2. If the potential difference between the parallel plates would be increased what would happen with the surface potential on the cylinder? What about the electric field within the cylinder?
3. What can you conclude about the potential and electrical fields inside hollow or solid uncharged conductive objects?
Homework Equations
Perhaps this may help but not really needed:
[tex]V_{f}-V_{i}=-\int_{i}^{f}\overrightarrow{E}\cdot d\overrightarrow{s}[/tex]
The Attempt at a Solution
1. I believe the electric field in a conductor is zero. Any excess charge is distributed to the surface. If an isolated conductor is placed in an external electric field all points of the conductor still come to a single potential regardless of whether the conductor has an excess charge. The free conduction electrons distribute themselves on the surface in such way that the electric field they produce at interior points cancels the external electric field.
2. Would the surface potential on the cylinder increase but the electric field in the cylinder stays zero? Stack more an more charge on the surface all you want, you aren't going to increase the electric field inside the cylinder. It will just distribute itself on the surface more and more.
3. The electric field inside is always zero? Any electrical potential is in regard to the surface of the conductors?
Here is my fantastic paint drawing if someone really needs it to picture the apparatus: