Displacement current inside capacitor

In summary, the conversation discusses a doubt about the solution given in the physics textbook "Physics for scientists and engineers" by Serway and Jewett. The individual points out that the author calculates the electric flux through the entire Amperian loop instead of just the area of the capacitor plates, which is inconsistent with the derivation of the expression for displacement current. It is then realized that the magnetic field at a certain distance from the center of the capacitor plates increases with distance, which is initially confusing until it is understood that the author is referring to a distance less than the radius of the plates. This understanding leads to the conclusion that the problem has been solved.
  • #1
issacnewton
1,004
31
Hi

I have already solved the problem. I just have some doubts about the solution given in the
solution manual. This is "Physics for scientists and engineers" by Serway, Jewett
In the solution for part b) , the author has taken the area of whole Amperian loop while
calculating the electric flux through it. The book itself derives the expression for the displacement current taking only the area of the capacitor plates, which makes sense , since
its probably assumed that the electric field outside the volume between the plates is zero.
So ,in the solution of the problem, the author derives the expression for the magnetic field at a distance r from the center of the capacitor plates as

[tex] B=\frac {\mu_{o} I r}{2A} [/tex]

it doesn't make sense that B increases as r, distance from the center of the capacitors,
increases.
 

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  • #2
I think I got it, The r at which the author asks for the magnetic field is less than the radius
of the capacitor plates. So we have to consider the area of the amperian loop only.
So problem is solved.
 

Related to Displacement current inside capacitor

1. What is displacement current inside a capacitor?

Displacement current is an electric current that is created inside a capacitor due to the changing electric field between its plates. It is not a flow of charge, but rather a flow of energy that occurs when the electric field changes over time.

2. How is displacement current different from conduction current?

Conduction current is the flow of charge through a material, while displacement current is a flow of energy through empty space. In a capacitor, conduction current only exists in the connecting wires, while displacement current exists between the plates.

3. What is the role of displacement current in electromagnetic waves?

Displacement current is an essential component in Maxwell's equations, which describe the behavior of electromagnetic waves. Without displacement current, these equations would not accurately predict the behavior of electromagnetic waves.

4. Does displacement current have any practical applications?

Yes, displacement current is used in various electronic devices, particularly in capacitors. It also plays a crucial role in wireless communication, as it allows for the transmission of electromagnetic waves through empty space.

5. How is displacement current related to capacitance?

The amount of displacement current inside a capacitor is directly proportional to its capacitance. This means that a capacitor with a larger capacitance will have a higher amount of displacement current when the electric field changes.

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