A student uses two bar magnets to create a uniform magnetic field. He places a current-carrying wire at right angles to the magnetic field, as shown in the figure below:
There is a force on the current-carrying wire.
The student wants to reverse the direction of the force on the wire. State one change that reverses the direction of the force on the wire.
The student increases the separation of the poles of the permanent magnets. State and explain how increasing the separation affects the force on the current-carrying wire.
