64. Wire coil radius R = 20 centimeters is located in the plane of the magnetic meridian. At the center of the loop with a small magnetic needle, which is able to rotate around a vertical axis. At what angle deflected arrow, but if you round to put current of I = 12 A? The horizontal component of the earth's magnetic field induction to take in equal = 20 mT.

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