# Basic Electricity Question - Potential Electric

cheechnchong

## Homework Statement

Question: a plate carries a charge of -3.0 uC, while a rod carries a charge of +2.0 uC. How many electrons must be transferred from the plate to the rod, so that both objects have the same charge?

## The Attempt at a Solution

N= q/e = -2.0e-6/-1.6e-19 = 1.25e13 electrons transferred

something doesn't seem right about this problem. the prof didnt mark this wrong, but he marked -2.0e-6 C wrong? anyone with the fix?

## Answers and Replies

Homework Helper
If you transfer 2uC from the rod to the plate, what will be the charges on both objects?

cheechnchong
If you transfer 2uC from the rod to the plate, what will be the charges on both objects?

-3.0 uC and +2.0 uC ...when you sum them up you get -1.0 uC? each with -0.5 uC? then, 2.5 uC when you subtract from 3.0 uC?

find how many electrons in 2.5 uC? is that how much is transferred?

too many questions!

denverdoc
think that's right, eg taking away from one and giveth to the other;
-3-deltaC=2+deltaC so -2.5uC

cheechnchong
^^that's it right? just calculate electrons for 2.5 uC and that's that right?

denverdoc
You're good best I can tell, but technically its -2.5uC, some profs might not care, others most definitely will.

Last edited:
cheechnchong
appreciate it doc. i'll go ahead and take your word.