Question

The structure of a generator and motor are physically identical. It is only a matter of whether the crank is mechanically moved by an applied force (torque for a rotating generator) or the electrical terminals are supplied with a current as to which the device acts as, either a motor or a generator.

A hand-held generator of DC electricity is used to charge a capacitor. The generator handle is cranked clockwise to produce a current to charge the capacitor.

When the crank is released and no longer is charging the capacitor, the capacitor discharges through the generator which now acts as a motor. Relative to the motion of the crank while charging, in which direction will the crank rotate as the capacitor is discharging? Briefly explain your answer. A successful answer might merely use the idea of "back" force. Diagrams are discouraged, drawn in 3D. Instead, use the convention of directions into and out of the page if you must use a diagram. Everything must be labeled clearly.

Answer 1