Magnetic Forces Example Problems


  1. A charge of +2.0 x 10-6 C is moving at 1.0 x 103 m/s at a distance of 120 mm away from a straight wire carrying a current of 4 A. Find the magnitude and direction of the force on the charge when it is moving parallel to the wire (a) in the same direction as the current and (b) in the opposite direction to the current.


  2. A certain electric transmission line consists of two wires 4 m apart that carry currents of 1 x 104 A. If the towers supporting the wires are 200 m apart, how much force does each current exert on the other between the towers ?