Line charge creating induced emf and displacement current

In summary, the conversation discusses a problem involving a long, straight wire with a time-varying line charge and a square wire loop located a distance a away from the wire. The goal is to find expressions for the displacement current at the center of the loop and the magnetic flux through the loop. The equations for displacement current and electric and magnetic flux are provided, but the individual is unsure how to set up the math and the relationship between the wire direction vector and the normal to the loop. Clarification is also needed on the meaning of "a" in the problem. A picture would be helpful in understanding the problem.
  • #1
gsmtiger18
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Homework Statement


A long, straight wire has a line charge, λ, that varies in time according to: λ = λ0 exp(-βt). A square wire loop of dimension a is located adjacent to the wire at a distance of a from the wire. Calculate expressions for the displacement current at the center of the wire loop and the magnetic flux through the loop.

a = the side length of the square wire loop.
λ0 = the initial charge of the line charge at time t = 0
β = I assume some kind of constant. I haven't encountered this variable in a displacement current problem before.

Homework Equations


idisp = ε0 * dΦe/dt
ε = -dΦm/dt
Φm = ∫B ⋅ dA
Φe = ∫E ⋅ dA = qenc / ∈0
∫ E ⋅ dl = -dΦm / dt

The Attempt at a Solution


I'm pretty sure I can find an expression for the electric field first by integrating the equation for the time-varying charge, but I'm not sure how to set that up. I think I should integrate with respect to time and treat radius as a constant. From the electric field I can use Faraday's Law to find the emf, but again I'm unsure as to how exactly to set up the math.
 
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  • #2
What is the juxtaposition between the wire direction vector and the normal to the loop? I.e if the wire vector is in the x direction, is the loop normal in the y or the z direction?

Is "a" the distance from the loop's center to the perpendicular distance to the wire, or is "a" the perpendicular distance from the closer collinear loop segment to the wire?

A picture would help immensely.
 
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Related to Line charge creating induced emf and displacement current

What is a line charge?

A line charge is a type of electric charge that is spread out along a one-dimensional path. It is typically represented by a line in diagrams and can be either positive or negative.

What is induced emf?

Induced emf, or electromotive force, is the voltage that is generated in a circuit due to a changing magnetic field. It is the force that drives the flow of electric current in a conductor.

How does a line charge create an induced emf?

When a line charge moves or changes in some way, it creates a changing electric field. This changing electric field then induces a magnetic field, which in turn creates an induced emf in any nearby conductors.

What is displacement current?

Displacement current is a type of electric current that is produced when a changing electric field passes through a given area. It is a crucial part of Maxwell's equations and is involved in the generation of electromagnetic waves.

How is displacement current related to induced emf?

Displacement current is directly related to induced emf, as it is the changing electric field that induces the magnetic field that creates the emf. In other words, displacement current is the mechanism by which induced emf is generated.

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