Recently I started "studying" electromagnetic induction (O.K. that might be a bit of an overstatement, but I am interested in it, so it's just as well) and I came to the following important "discoveries":(adsbygoogle = window.adsbygoogle || []).push({});

- one of the Maxwell's equations states (Faraday's law if my memory serves me correct) that given anyfixedsurface with its border, the voltage "induced" on this border (but more importnatly just the voltage in the sense of the integral of the electric field along this border) equals the negative time derivative of the magnetic flux through this surface;

- suppose a "material" loop is placed inside a static homogenous magnetic field (the loop is not just imaginary) and suppose we are stretching it or that it rotates or whatever as long as its surface vector is changing. Then there will also be an "induced" voltage in this loop and it will again equal the negative time derivative of the magnetic flux through this surface. Just that this time I would claim that this "induced" voltage is notthevoltage (in the sense given above) but rather an "effective" voltage of sorts, in the sense that its effect for almost all intents and purposes is the same as if indeed there was a real voltage present. My claim is a bit presumptuous and I'm not quite sure whether or not it holds but I amquitesure. In any case I would like it for you to tell me how "wrong" I am . Also note that I am ignoring whatever fields the elctrons themselves produce in this case as this would complicate matters greately but I don't think it fundamentally hurts the analysis. Or am I wrong again? ;

- suppose the field changes as well as the surface vector. Again the "effective" voltage (as I would like to put it) is the time derivative of the magentic flux (negative, to be precise).

My teacher disagrees with me and says that the voltage is "real" in all cases and, naturally, I disagree with him. Feel free to do the same, but please argument (I know I haven't been doing much of that but I'm asking you to be better than me ), better still, tell me I'm right.

Thanks for your answers.

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# Magnetic induction, Faraday's law and the likes

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