Electrically connected charged balls

  • Thread starter Thread starter Bashyboy
  • Start date Start date
  • Tags Tags
    Balls Charged
AI Thread Summary
The discussion centers on the relationship between the charge of a ball, its radius, and electric potential, emphasizing that potential is directly proportional to charge and inversely proportional to radius. When two charged balls are connected by a conductive wire, charge redistributes until both reach the same electric potential. However, this does not imply that the charges on both balls are equal unless they have identical radii. The application of Gauss's Law confirms that the potential outside a charged sphere behaves as if all charge is concentrated at its center. Understanding these principles is crucial for solving related physics problems.
Bashyboy
Messages
1,419
Reaction score
5
Hello,

I am reading through the problem given in this link: http://physicstasks.eu/uloha.php?uloha=300

There is one sentence I am particularly unsure of, "Charged ball's potential is in direct proportion to the charge of the ball and in reciprocal proportion to the ball's radius."

Why is this true? Is there some derivation for this?

Also, here is a passage I have a question about:

"When the balls are connected by a conductive wire, the charge can move from one ball to other. The ball with higher potential will be partly discharged trough the wire while charging the other ball. At the end of this process, both balls' potentials will be the same."

When the two sphere's are at the same electric potential, does this mean that each ball has the same amount of charge?
 
Physics news on Phys.org
The equation is Gausses Law.
The result for a ball of charge is that the potential at radius r ≥ R (where R is the radius of the ball) is the same as if all the charge in/on the ball were concentrated at the center.

If the two spheres are at the same electric potential, they will not have the same charge unless they have the same radius. This follows from the previous result.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...
Back
Top