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I am wondering about why armatures are being rotated instead of being static? The magnetic flux will still cut the armature windings and because of this induced current will be generated. So, why it is being rotated instead of being static?

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  • $\begingroup$ There needs to be a changing magnetic flux, but this can be done by rotating a magnet instead of by rotating an armature. $\endgroup$
    – Peter
    Commented Jun 18, 2022 at 8:13

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Just having magnetic flux going through a circuit isn't enough to induce an EMF. By Faraday's law, the induced voltage is proportional to the rate of change of the magnetic flux, not the flux itself. For a static winding, the magnetic flux will be static, i.e. the rate of change and hence the induced voltage are zero. For a rotating armature however, the magnetic flux cutting the windings is time dependent, which generates a voltage.

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  • $\begingroup$ But when the pole windings do not conduct current, There is no magnetic flux through the Armature windings. As soon as the armature winding is to a voltage source, current will pass through it and it will generate some magnetic flux, the flux will cut the armature winding and there will be a change of flux( as there is no flux when no current is passing through the armature winding). So am induced e.m.f/current should be generated through the armature winding right? $\endgroup$ Commented Jun 18, 2022 at 7:37
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    $\begingroup$ Sorry but if we're talking about a generator, the armature winding won't be connected to a voltage source at any point. It'll be connected to a load. Also, there is flux even if the winding isn't passing current, the flux is supplied by the permanent magnet in the generator. $\endgroup$ Commented Jun 18, 2022 at 7:46
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To generate an induced voltage you do not need just a magnetic flux linked with the armature you need a changing magnetic flux linked with the armature.

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  • $\begingroup$ But when the pole windings do not conduct current, There is no magnetic flux through the Armature windings. As soon as the armature winding is to a voltage source, current will pass through it and it will generate some magnetic flux, the flux will cut the armature winding and there will be a change of flux( as there is no flux when no current is passing through the armature winding). So am induced e.m.f/current should be generated through the armature winding right? $\endgroup$ Commented Jun 18, 2022 at 7:38

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