- #1

tony873004

Science Advisor

Gold Member

- 1,749

- 141

**1. Homework Statement**

A parallel plate capacitor with A=125 cm

^{2}and d=1.25 mm is charged to a potential difference of 10.0 V. What is the charge density on each plate?

**2. Homework Equations**

[tex]

V = \frac{{\sigma d}}{{\varepsilon _0 }}\,\,\,\, \Rightarrow \,\,\,\,V\varepsilon _0 = \sigma d\,\,\,\, \Rightarrow \,\,\,\,\sigma = \frac{{V\varepsilon _0 }}{d}

[/tex]

**3. The Attempt at a Solution**

Plugging in numbers, I get 8.5*10

^{-8}C/m

^{2}. But I never used the Area. My units seem to work. Did they throw in irrelavant data? Shouldn't I only need Area if I want total charge?

Should my answer be half of what I computed, because it is divided between 2 plates?

**1. Homework Statement**

**2. Homework Equations**

**3. The Attempt at a Solution**