14. Robert Millikan received a Nobel Prize for determining the charge on the electron. To do this, he set up a potential difference between two horizontal parallel metal plates. He then sprayed drops of oil between the plates and adjusted the potential difference until drops of a certain size remained suspended at rest between the plates, as shown above. Suppose that when the potential difference between the plates is adjusted until the electric field is 1.00 x 10# N/C downward, a certain drop with a mass of 3.27 x 10 15 kg remains suspended. a. What is the charge on this drop? (4 marks) b. If the distance between the plates is 0.010 m, what is the battery's potential