A charged oil drop is suspended in air between two parallel metal plates as shown below. Oil drop Show me how to solve part b Choose the correct answers to complete the sentences below. a. The weight of the oil drop was measured to be 3.2 107 N and the strength of the electric field between the two parallel plates is 7.5 103 V/m.. The charge of the oil drop is 4.3 v 10-11 C. b. The number of subatomic particles that make up the charge of the oil drop is 2.6 108.