Electromagnetism issues need clearing up

AI Thread Summary
In electromagnetism, the relationship between mutual inductance, the number of turns in each coil, the current in the primary coil, and the induced emf in the secondary coil is crucial for understanding transformers. The magnetic field strength (B) is influenced by the permeability of free space (u_0), the number of turns (N), and the current (I) in the primary coil. The induced emf (E) in the secondary coil is determined by the rate of change of magnetic flux (ψ) and can be expressed using the inductance (L) of the coil. Mutual inductance (M) describes how a change in current in one coil induces emf in another, with the relationship given by E = MdI/dt. Clarifying the distinction between self-inductance and mutual inductance is essential for solving related problems effectively.
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In electromagnetism, when there is an emf is induced in a secondary coil from a current flowing in a nearby primary coil (such as in a transformer), then how is the mutual inductance, number of turns of each coil, the current in the primary coil, and the emf in the secondary coil related?

From the reading that I have been doing, I think that for a single coil:
B = \frac{u_0NI}{2 \pi r}
Where the u_0 is the permeability of free space (I don't know how to get the proper symbol), N is the number of turns, and B is the magnetic field strength.

From what I have gathered from the reading, is:
E = -\frac{d \psi}{dt} = -L \frac{dI}{dt}
Where I have used E for emf, and psi for the flux (I don't know how to get the convention symbol), and L is the inductance of the secondary coil, however, I am unsure as to how the mutual inductance (M) is related to the inductance (L).

I think the problem is that when people speak of inductance, I am unsure what they mean the inductance of.

The reason why I am asking is that I have a question which uses this idea, but I am so close to getting it, that I would rather not post the problem in the homework section.

Thanks in advance.
 
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ppyadof said:
In electromagnetism, when there is an emf is induced in a secondary coil from a current flowing in a nearby primary coil (such as in a transformer), then how is the mutual inductance, number of turns of each coil, the current in the primary coil, and the emf in the secondary coil related?

From the reading that I have been doing, I think that for a single coil:
B = \frac{u_0NI}{2 \pi r}
Where the u_0 is the permeability of free space (I don't know how to get the proper symbol), N is the number of turns, and B is the magnetic field strength.

From what I have gathered from the reading, is:
E = -\frac{d \psi}{dt} = -L \frac{dI}{dt}
Where I have used E for emf, and psi for the flux (I don't know how to get the convention symbol), and L is the inductance of the secondary coil, however, I am unsure as to how the mutual inductance (M) is related to the inductance (L).

I think the problem is that when people speak of inductance, I am unsure what they mean the inductance of.

The reason why I am asking is that I have a question which uses this idea, but I am so close to getting it, that I would rather not post the problem in the homework section.
L, self inductance, is the ratio of induced emf in an inductor (coil) to rate of change of current in that inductor: Emf = L dI/dt

Mutual inductance relates to two coils in which a change of current in one coil induces an emf in the other. Emf = MdI/dt where Emf is the emf in the other coil.

AM
 
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