Millikan oil drop experiment potential difference

[AMMax]

Homework Statement

in a Millikan oil drop experiment, a uniform electric filed of 1.92 x 10^5 N/C is maintained in a region between two plates separated by 1.5 cm. Find the potential difference between the plates.

Homework Equations

mg = q x E

The Attempt at a Solution

in order to find the q and hence find the voltage/potential you need to have mass. there is no mass given. I assume once you have mass you get q and from there you can find voltage using k(q/r)

 

[Stonebridge]

To find V, the pd between the plates:
In a uniform electric field between parallel plates, the field can be calculated from the potential gradient. You have the field strength given and you know the plate separation.
Does this help?