1. In a Millikan type experiment, two horizontal plates are 2.5 cm apart. A latex sphere of
mass 1.5 x 10-15 kg remains stationary when the potential difference between the
plates is 460 V, with the upper plate positive. [2+2+2+2 = 8 marks]
a. Is the sphere charged negatively or positively?
b. What is the magnitude of the electric field intensity between the plates?
C. Calculate the magnitude of the charge on the latex sphere.
d. How many excess or deficit electrons does the sphere have?

The sphere us negatively charged. In a Millikan type experiment, there will be two forces that will be acting on the sphere which are the electric force which acts upward and also the gravity which acts downward.

Because the upper plate is positively charged, there'll what an attractive curve with an upward direction which will be felt by the negatively charged sphere.

b. What is the magnitude of the electric field intensity between the plates?

The magnitude of the electric field intensity between the plates is 18400v/m.

C. Calculate the magnitude of the charge on the latex sphere.

The magnitude of the charge on the latex sphere hae been solved and attached

d. How many excess or deficit electrons does the sphere have?

There are 5 excess electrons that the sphere has.

Check the attachment for further explanation.