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manvin
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I was just thinking about the "changing magnetic field through a loop induces an EMF" and thought of a conceptual question I'm having trouble with. So, imagine you have an open surface where there's a changing magnetic flux that you know (say its a plane of magnetic field coming toward you changing at B=5t) now you take an arbitrary loop that does not conduct any current, and then the same arbitrary loop that does conduct current. In the first case, the EMF should be equal to dB/dT * A, or 5*A. In the second case, where current CAN flow (say through a copper conductor of resistance R) there is now an opposing magnetic flux generated by the induced current, and so the equation for the magnetic field in the center of the loop is now altered. It seems that in this case, you can no longer say that the EMF is 5*A, because the magnetic field equation is no longer B=5t since it is altered by the current inside the conductor, yet dB/dt * A = EMF still holds... Is this right? I'm sorry for the messy confusing description but if anyone can see where I'm coming from please try and answer. Thank you