72. Next to the long straight wire which carries the current I1 = 10,0 A is a square frame with a current I2 = 1,00 A. Frame and wire lie in one plane. Passing through the middle of the opposite sides of the axis parallel to the frame and spaced apart from it by a distance b = 100 mm. Side frames a = 80 mm. Find the force F, acting on the frame, and the work of A, which must be performed in order to turn the frame around its axis 180°.

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