Inductance in an AC generator.

[Yuqing]

I just have some confusion about whether or not self-inductance will occur in an AC generator.

The current is alternating in both direction and magnitude rapidly when it is generated and this will in turn cause a changing magnetic field around the conductor. This magnetic field will then induce a back-emf which opposes the change. Does this happen inside the generator as well? If it does happen, then does the rotation speed of the armature linearly relate to the current produced or does this inductance (inductance increases with frequency right?) somehow throw it off?

Edit: I just realized that the question is awkward and difficult to grasp. Perhaps this second question will be able to clarify some things for me.

Say I induce a current in a solenoid through the movement of a magnet. If the magnet was moved at constant velocity then the emf generated would be constant. However, if the magnet was accelerated, the emf generated would increase with the velocity and this would cause an increasing current. Would this increase in current cause self-inductance in the solenoid?

 

[LightHero]

Yes, self-inductance will occur in an AC generator. This is because the changing current in the generator will create a changing magnetic field around the conductor, which will induce a back-emf that opposes the change. This back-emf will limit the rate of change of the current, and therefore limit the rate of change of the magnetic field. The rotation speed of the armature will still linearly relate to the current produced, but this inductance will cause a slight delay in the response of the current to changes in the field.In regards to your second question, yes, an increase in current caused by acceleration of a magnet will cause self-inductance in the solenoid. This is because the changing current will again create a changing magnetic field, which will induce a back-emf that opposes the change. This will again limit the rate of change of the current and therefore limit the rate of change of the magnetic field.

 

[astrokreng]

Dear student,

Thank you for your question. Inductance is a fundamental property of any circuit or system that involves changing current or magnetic fields. In an AC generator, the current is constantly changing direction and magnitude, which results in a changing magnetic field around the conductor. This changing magnetic field induces a back-emf, which opposes the change in current.

This back-emf is a form of self-inductance, as it is caused by the changing magnetic field produced by the current in the generator. This self-inductance does occur inside the generator and can affect the output current and voltage. The rotation speed of the armature does have a linear relationship with the current produced, but the inductance can also affect this relationship by opposing the change in current.

To answer your second question, if a current is induced in a solenoid through the movement of a magnet, the emf generated will be proportional to the velocity of the magnet. This increase in velocity will result in a stronger magnetic field and therefore a higher emf and current. This increase in current will also cause self-inductance in the solenoid, as the changing current will produce a changing magnetic field, which will induce a back-emf.

I hope this clarifies your confusion about self-inductance in an AC generator. Inductance is a complex concept and can be difficult to grasp, but it is an important factor in understanding the behavior of electrical circuits and systems. If you have any further questions, please do not hesitate to ask.

Best regards,