Two current carrying wires, both with a current of 4 A, are separated by 0.4 m. Both wires are positioned vertically, and have their current directed upwards. Find the magnitude and direction of the magnetic field at a point 0.1 m right of the left wire.

A proton travels with a speed of 3.00 106 m/s at an angle of 37.0 with the direction of a magnetic field of 0.300 T in the +y direction. What are (a) the magnitude of the magnetic force on the proton and (b) its acceleration?

A long, straight, horizontal wire carries a left-to-right current of 20 A. If the wire is placed in a uniform magnetic field of magnitude 4.0105 T that is directed vertically downward, what is tire resultant magnitude of the magnetic field 20 cm above the wire? 20 cm below the wire?

12.4 Check Your Understanding Two wires, both carrying current out of the page, have a current of magnitude 2.0 mA and 3.0 mA, respectively. The first wire is located at (0.0 cm, 5.0 cm) while the other wire is located at (12.0 cm, 0.0 cm). What is the magnitude of the magnetic force per unit length of the first wire on the second and the second wire on the first?