A rectangular current loop is placed in a uniform magnetic field. The net force on the loop is

1. The four sides of the loop experience forces from F = IL × B. 2. Opposite sides carry currents in opposite directions, giving equal-and-opposite forces. 3. The vector sum of the four forces cancels in a uniform field. 4. A non-zero net torque can still act, but the net force is zero. _Source: syllabus Physics Ch 4 "Moving Charges and Magnetism", §4.10.1_