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(Part 2) A special metal S conducts electricity without any resistance. A closed wire loop, made of S, does not allow any change in flux through itself by inducing a suitable current to generate a compensating flux. The induced current in the loop cannot decay due to its zero resistance. This current gives rise to a magnetic moment which in turn reples the source of the magnetic field or flux. A magnetic dipole of moment m is brought along the axis of this loop from infinity to r is much, much less than a. The magnitude of the dipole’s magnetic field is (u0)(m)/[2(pi)r^3]. The magnitude of the force between the two magnetic dipoles with moments m1 and m2 is (k)(m1)(m2)/(r^4). The work done in bringing the dipole from infinity to r is proportional to:
A) m/r^5
B) m^2/r^5
C) m^2/r^6
D) m^2/r^7

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