Ampere's Law Problem

1. Apr 9, 2005

Merrank

The question is:

Between two long parallel cylinders of radius "a" and "b" (non-coaxial) and an axal separation of "c", a steady current of "I" flows. (See attachment below) Show that the inner cylinder (radius "a") has a constant magnetic field. Use Ampere's Law. Indicate all steps clearly. [Hint: 0 = 1 + (-1)]

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• s Law Problem.bmp
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2. Apr 10, 2005

Andrew Mason

You have to use the principle of superposition. Work out the field for the large cylinder having a uniform current density (ie. uniform over its cross-sectional area) using Ampere's law; then work out the field for the small cylinder with a current flowing in the opposite direction with a cross-sectional density that that is the same magnitude (but opposite in direction) to that of the larger cylinder. Superimpose the two (add the field vectors).

AM