# DQ5C_solution - Discussion Question 5C P212 Week 5...

This preview shows pages 1–2. Sign up to view the full content.

Discussion Question 5C P212, Week 5 Designing a Capacitor 1 A capacitor is nothing more than two conducting objects (called terminals ) that are separated by an insulating medium. If we attach a battery to such an object, a charge +Q will accumulate on one of the plates, and an equal and opposite charge –Q will accumulate on the other. That’s the purpose of a capacitor: it’s a device to store charge. Knowing that helps us remember the formula for capacitance, C = Q / Δ V a “ big ” capacitor (large C ) can store a lot of charge with little voltage. Let’s build one! Two large circular plates made of metal have area A = 2 m 2 . They are arranged parallel to each other and are separated by a distance d = 1.5 cm. The gap between the plates is filled with air. Together, the plates form a parallel-plate capacitor . (a) Where do the charges go? 1. Place a charge + Q on one terminal and a charge – Q on the other. Write down the surface charge densities, σ i and σ o , for the inner and outer surfaces of each plate.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 06/16/2011 for the course PHYS 212 taught by Professor Kim during the Spring '08 term at University of Illinois, Urbana Champaign.

### Page1 / 2

DQ5C_solution - Discussion Question 5C P212 Week 5...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online