90. The coil length l = 50 cm, with a cross-section S = 40 cm 2 consists of one row of tightly abutting turns of wire with a diameter d = 0,60 mm. on the coil terminal voltage U = 12 V. Determine the strength of the current I in the coil, if during the time t = 0,40 ms in the wire is released quantity of heat equal to the energy of the magnetic field coil. The field inside the coil considered uniform.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)