# Potential Difference Help

1. Apr 17, 2006

### mlowery

Here is the question:
A parallel-plate capacitor is made of two circular plates, each with a diameter of .0025m. The plates of this capcitor are separated by a space of .00014m. What is the potential difference between a point midway between the plates and a point that is .00011m from one of the plates?

$$\Delta V = 3.4 * 10^{-2} V$$
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I know the potential difference between two points is given by:
$$\delta V= \frac {\Delta PE} {q}= -E \Delta d$$

I also know:
$$\delta PE = -qE \Delta d = k_{c} \frac {q_{1} q_{2} } {r}$$

Somewhere, I am not seeing how the components fit together. Also, I am having trouble because the charges of each point are not given. Can I assume them to be equal?

Last edited by a moderator: Apr 18, 2006