Static Electric Fields: Interactions Explored

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Discussion Overview

The discussion centers on the interactions of static electric fields, particularly in the context of uniform charge distributions along wires and spheres, as well as the behavior of electric fields in capacitors. Participants explore the nature of electric field lines, charge interactions, and the implications of Gauss's law.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions the interactions between charges in a uniform distribution and whether adjacent charges influence each other, particularly in the context of capacitors.
  • Another participant asserts that charges do interact by repelling each other and explains that static charges on a conductor reside on the surface due to this repulsion.
  • A participant expresses confusion about the representation of electric fields from uniformly charged objects, noting that only a single field appears to be shown despite the presence of multiple charges.
  • There is a discussion about how electric field lines can cancel out due to the presence of multiple charges, leading to a net field that is perpendicular to the surface of a conductor.
  • One participant seeks clarification on why a charge at one end of a linear charge distribution does not cause electric flux on the plates of a cylindrical Gaussian surface, referencing Gauss's law and the apparent neglect of some flux in diagrams.
  • Another participant explains that Gauss's law is most accurate for infinitely long charged wires or cylinders and that it serves as an approximation for finite lengths.

Areas of Agreement / Disagreement

Participants express differing views on the nature of charge interactions and the implications of electric field representations. There is no consensus on the specifics of how electric fields behave in various scenarios, and the discussion remains unresolved regarding the nuances of Gauss's law and electric flux.

Contextual Notes

Some assumptions about charge distributions and the applicability of Gauss's law are not fully explored, and the discussion includes unresolved questions about the behavior of electric fields in certain configurations.

Godwin Kessy
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Jus chek out careful when we have uniform electric charge distribution along wire or a sphere etc! Is there no any interaction between the charges in that uniform distribution!

then look at the capacitor we only see straight field lines from positive charged plate to the negative charged plate are no more electric interaction that i expected ie. Between the adjacent charges on a plate or between two different charges in two different plates that are not connected by a straight horizontal field line!

may anyone help me out on what really hapens?
 
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The charges do interact. :smile: They repel each other.

You may have heard that within a charged conductor, the (excess) static charges are always on the surface (and only on the surface). That's because they are repelling each other. In essence, they are "trying" to get as far away as they can from any other charge or group of charges. But since all the other charges are "trying" to the same thing, they just end up spreading out over the surface. Eventually, the charge distribution of the surface charges on a conductor align themselves in just such a way that the electric field in the conductor is 0.

Your textbook might not show the electric field lines in between charges on the same plate, only because it's probably not relevant to the problem. But they are there.

And the electric field lines in-between the plates do curve somewhat as you move toward the edge. Often this is ignored in a typical capacitor because the distance between the plates is so tiny compared to the length of the plates.
 
Thanks man! But what i know is that every charge radiates electric fields radialy outwards

but what i clearly see on a uniformly charged object is that only a single field among many seems to be shown

also what hapens until a charge on one end of a linear charge distributed conductor can't cause electric flux on the plates of the cylindrical gausian surface drawn!

may u tel me clearly on the interaction and at the same time gauss law says that the net sum of flux is the algebraic sum of the flux due to each charge while the diagram shows that some flux are neglected and i don't really understand what hapens to it?
 
Godwin Kessy said:
Thanks man! But what i know is that every charge radiates electric fields radialy outwards

Yes, but since there are many charges being modeled (an infinite amount of infinitesimal charges in a uniformly charged object), the electric field often cancels out in all components except for the component perpendicular to the surface (this is certainly true for a conductor).

Imagine an infinitely long, charged wire laying horizontally on the x-axis. A given infinitesimal point charge will have electric field lines drawn spherically outward. So some of its electric field will be drawn in the general direction of the positive x direction. But there is also another infinitesimal charge right next to it, slightly further along the x-axis, who's field lines point in the negative x-axis direction (in-part), canceling out the field line components of the first charge, but only in the x direction. Now if you put an infinite amount of infinitesimal charges on the line all electric field lines cancel except for the field lines pointing radially away from the line.

but what i clearly see on a uniformly charged object is that only a single field among many seems to be shown

Yes, this is due to cancellation of the different components of the different charges. Everything sums up to zero, except for the component pointing radially outward. In a charged conductor, this direction is always perpendicular to the surface, when measured at the surface itself.

also what hapens until a charge on one end of a linear charge distributed conductor can't cause electric flux on the plates of the cylindrical gausian surface drawn!

may u tel me clearly on the interaction and at the same time gauss law says that the net sum of flux is the algebraic sum of the flux due to each charge while the diagram shows that some flux are neglected and i don't really understand what hapens to it?

Gauss' law only works for an infinitely long charged wire or cylinder, when using a cylindrical Gaussian surface. If the charged wire/cylinder is less than infinitely long, Gauss' law is only an approximation. But it's a pretty good approximation if the place of interest is not near one of the edges, and if the distance to the cylinder/wire is small compared to the length of the cylinder/wire.
 
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