- #1
Chen
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Let's say I want to calculate the magnetic field at a distance d from the center of a wire of finite length L, carrying a current I. Why would it be wrong to apply Ampere's law to a circular path of radius d centered on the wire, and say that the integral of B.dl is simply B times 2pi*d? (obviously it gives the wrong answer...)
Is the magnetic field not constant along this circular path? I would say so - the problem obviously has cylindrical symmetry.
Is it not parallel to the path at all points? I would think so - from Biot-Savart's law applied to every small element of the wire.
So where is the mistake in this logic?
Thanks,
Is the magnetic field not constant along this circular path? I would say so - the problem obviously has cylindrical symmetry.
Is it not parallel to the path at all points? I would think so - from Biot-Savart's law applied to every small element of the wire.
So where is the mistake in this logic?
Thanks,