# Homework Help: How to solve for the capacitance of an interlocking plates

1. Jun 19, 2009

### mba444

1. The problem statement, all variables and given/known data

A capacitor is constructed of interlocking
plates as shown in the figure (a cross-sectional
plates is 1.26 mm, and the effective area of
one of the adjacent plates is 6.1 cm2.

The permittivity of a vacuum is 8.85419 × 10−12 C2/N · m2.
Ignoring side effects, calculate the capaci-
tance of this unit. Answer in units of pF.

2. Relevant equations

C=(Eo*A)/d

3. The attempt at a solution

what i did is that i assumed that the capacitors are parrallel therefore i used this equation by plugging the given values .. but still i keep getting the wrong answer ..

i am looking forward for your help

Last edited by a moderator: May 4, 2017
2. Jun 19, 2009

### drizzle

hey mba444, welcome to PF :)
how many capacitors you assumed that are parrallel?

3. Jun 19, 2009

### mba444

thanx for welcoming

2

4. Jun 19, 2009

### drizzle

sure not:tongue:, you know that each capacitor have two plates separated by the vacuum now look again at the pic, got it?!...

5. Jun 19, 2009

### mba444

Ohhh

thereore 8

thanx alot :shy: