Answer to Question #159812 in Electric Circuits for zain ul abdeen

Question

 A wire is formed into a circle having a diameter of 10.0 cm and placed in a uniform magnetic field of 3.00 mT. The wire carries a current of 5.00 A. Find (a) the maximum torque on the wire and (b) the range of potential energies of the wire–field system for different orientations of the circle. 

Answer 1

$a) \tau_{max}=MB=IAB=l\pi r^{2}=5\times \pi$

$=375\pi \times 10^{-7}NM$

b) $U_{max}=+MB, U_{min}=-MB$