Part5

3c.

With the power supply off, discharge the sphere completely (with a wire connected to the ground) and increase the plate voltage to 2 kV. Use a plastic ruler to move the sphere to touch the positive plate but don't let it swing. Let it hang between the plates in a charged condition and observe what happens. If there is a charged body Q in an electric field E, shouldn't a force F = Q E be exerted on the sphere? Why does it not deflect or start to oscillate from rest?