Does a Decreasing Magnetic Field Induce Conventional Current?

In summary: That's the only way current can flow.think about it this way, there is energy stored in the magnetic field and that energy has to go somewhere.Yes, through the circuit and into the load.and that does not help at all, gran(d)pahow do you suppose that transformers work?Transformers work by using Faraday's Law of Induction to induce a voltage in a secondary coil that is proportional to the voltage in the primary coil. This allows for the transfer of energy from one circuit to another without the need for physical connection.
  • #1
learning_phys
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[tex] \xi = - \frac{dB}{dt} [/tex]

Is the emf induced by a changing flux. Is the current created by this emf conventional current?

For example. Say there is a square loop in the plane of this page, with a decreasing magnetic field going INTO this page. This creates a clockwise current to battle the change in B. Now say there was a voltage supply attached to this loop so it looks like this:

|----------|
| x x x x x |
| x x x x x |
|---l |-----|
-V+

The voltage V gives a conventional current to go clockwise. Would the current introduced by scenario above add do this voltage or subtract?

I guess my question is, is the clockwise current induced by the decreasing magnetic field a conventional current?
 
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  • #2


think about it this way, there is energy stored in the magnetic field and that energy has to go somewhere.
 
  • #3


and that does not help at all, gran(d)pa
 
  • #4


how do you suppose that transformers work?
 
  • #5


learning_phys said:
[tex] \xi = - \frac{dB}{dt} [/tex]
Is the emf induced by a changing flux.
Yes.
Is the current created by this emf conventional current?
Actually it's voltage by Faraday's Law of Induction. If there is an impedance for it to operate on then current flows.
For example. Say there is a square loop in the plane of this page, with a decreasing magnetic field going INTO this page. This creates a clockwise current to battle the change in B. Now say there was a voltage supply attached to this loop so it looks like this:

|----------|
| x x x x x |
| x x x x x |
|---l |-----|
-V+

The voltage V gives a conventional current to go clockwise. Would the current introduced by scenario above add do this voltage or subtract?
By the right hand rule the current would be clockwise as well.
I guess my question is, is the clockwise current induced by the decreasing magnetic field a conventional current?
Yes. It's a conductor. Presumably it has impedence somewhere in the circuit.
 

FAQ: Does a Decreasing Magnetic Field Induce Conventional Current?

What is "emf induced by a changing flux"?

"Emf induced by a changing flux" refers to the electromotive force (emf) that is created when there is a change in the magnetic flux through a conductor. This change in flux can be caused by moving a magnet, changing the current in a nearby wire, or other factors.

How is "emf induced by a changing flux" calculated?

The emf induced by a changing flux can be calculated using Faraday's Law, which states that the magnitude of the induced emf is equal to the rate of change of the magnetic flux through the conductor. This can be represented mathematically as: emf = -N(dΦ/dt), where N is the number of turns in the conductor and dΦ/dt is the rate of change of magnetic flux.

What is the relationship between "emf induced by a changing flux" and Lenz's Law?

Lenz's Law states that the direction of the induced emf is such that it opposes the change in magnetic flux that produced it. This means that if the magnetic flux through a conductor is increasing, the induced emf will create a current that produces a magnetic field in the opposite direction, and vice versa.

What are some real-world applications of "emf induced by a changing flux"?

The phenomenon of emf induced by a changing flux is used in many devices, such as generators, transformers, and motors. It is also the principle behind electromagnetic induction, which is used in technologies such as wireless charging, induction cooktops, and magnetic levitation trains.

What factors can affect the magnitude of "emf induced by a changing flux"?

The magnitude of the induced emf depends on several factors, including the rate of change of magnetic flux, the number of turns in the conductor, the strength of the magnetic field, and the resistance of the conductor. Additionally, the size and shape of the conductor, as well as its orientation to the magnetic field, can also affect the induced emf.

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