A hand cranked (Genecon) generator charges a 1 Farad capacitor. When the handle is released, the generator is now a motor powered by the capacitor. Will the handle rotate in the same direction as when charging the capacitor? Or will the handle rotate in the opposite direction?
Connect the Genecon generator to the 1F capacitor so that the capacitor will be charged when the handle is turned clockwise. Release the generator handle and the handle will turn because the generator is now a motor powered by the charged capacitor. Show the class which direction the handle turns.
1) Carl E. Mungan; Motor Demonstration Using a Hand-Cranked Genecon. The Physics Teacher 1.October.2014; 52 (7): 422-425. [PDF]
2) See also Generator and Inductor (5K40.80).