DOC PREVIEW
MIT 8 02X - Electricity and Magnetism

This preview shows page 1-2-3-4-5 out of 14 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 14 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Electricity and MagnetismMore on Electric PotentialMore on Electric PotentialMore on Electric PotentialCharge and PotentialCharge and PotentialCapacitanceCapacitanceCapacitanceCapacitorParallel Plate CapacitorParallel Plate CapacitorParallel Plate CapacitorParallel Plate CapacitorMar 4 2002Electricity and Magnetism•Electric Potential– Electric Field and Electric Potential– CapacitorsMar 4 2002More on Electric Potential• Where do charges go?++++++++++++++++Mar 4 2002More on Electric Potential++++++++++r0r1Mar 4 2002More on Electric Potential• Practical application– Lightning rod: Pointy tip -> small r!++++++++++r0r1Mar 4 2002Charge and Potential• Potential is proportional to ChargerRV=kQ/R2*kQ/R+++++++RMar 4 2002Charge and Potential• Potential is proportional to Charge– V * constant = Q•True for any object– true for point charge– Superposition principle•Define – Q = C V -> C is called CapacitanceMar 4 2002Capacitance• [Capacitance] = [C/V] = Farad– 1 Farad is huge•Sphere–C = R/k– The bigger the sphere, the bigger the capacitanceMar 4 2002CapacitanceQVQ = C*V => V = Q/Cslope = 1/CC smallC bigMar 4 2002Capacitance• Example C(Earth):C = 6*106m /9*109Nm2/C2 = 540 µFarad– Small capacitance– Potential increases quickly with charge– Hard to put charge on sphere – For sphere, reference point is r=infinity– How to build better device?Mar 4 2002Capacitor• Better capacity– don’t get charges from infinity, but from other object close-by• Capacitor–Def: Two conductors separated by insulator• Example: Parallel plate capacitorMar 4 2002Parallel Plate Capacitor+++++++++++-----------d-Q-QMar 4 2002Parallel Plate Capacitor+++++++++++------------Q -QdMar 4 2002Parallel Plate Capacitor• Depends only on Geometry!– like it did for sphere• To store lots of charge–make A big– make d small+++++++++++-----------d-Q-QC = ε0A/dMar 4 2002Parallel Plate CapacitorC=ε0A/dslope = 1/CV+++++++++++------------Q


View Full Document

MIT 8 02X - Electricity and Magnetism

Download Electricity and Magnetism
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Electricity and Magnetism and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Electricity and Magnetism 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?