ch33_ddjs

33.1 **electric feilds.**

Electrical feilds are created around any charged object that can create force on another charged object within the feild. (similar to gravitational feilds) Observe the feild created around the live wire above.

33.2 **electric feild lines**

A electrical feild overlapping other charges can be shown by drawing lines to represent the strength and direction of the feild. (pages 519 - 520 in book) There are three rules tpo always remember when demonstraighting electric feild lines.

1.) be sure that lines start on + and end on -, positive lines can not be drawn to positive lines, or negitive to negitive.

2.) The quantity of lines is based on the charges magnitude of the feild. ( more charge = more lines )

3.) No lines can ever cross over eachother, no overlapping, no crisscrossing, nada, zip, nei, none.



33.3 **Electric sheilding**

Static charges bouncing on a conductor force away ifrom eachpother n order to isolate themselves. this will cause the charges to collect on the outer suface of the conductor with no unbalanced charges in the middle. it also causes the lagest collaection of charges to accure where the radial curviture of the conducter is tinyest. the smaller the end, the more charge collects.

33.4 **Electrical Potential Energy**

Potential energey if found where work has been done to move a object. Work is needed to move things in an electrical feild just like objects in earth's gravity. The work done in an electrical feild is stored in the object as electric potential energy, and can be reversed by having the object return to its origin.

33.5 **Electric Potential**

Electric potential is found when charge on an object has moived it in some way.

//**Electric Potential = ( Electric Potential Energy / Charge )**//

Electric Potentialm is measured in joules of energy per coulomb of charge, ( volt ) because the units its measured in are called voltage.

33.6 **Electric Energy Storage**

Electric energy can be stored in capasitors, capasitors are made with 2 plates or strips inside them, one will have a positive and the other a negitive charge, placing the plates close togather with a insolater inbetween makes the opposite charges stay inplace until they are equalized, this can be done by putting a current throughthe plates or strips.

33.7 **The Van de Graaff Generator**

The Van de Graaff Generator is a machine used to build very high electrical voltage on a metal dome whcih can be used for experiments, demonstrations, etc. (seee picture on pg 527 of text book ) It functions by making a static charge thats placed on a moving belt in the bottom. the belt then carries the static charge to the top of the machine in the dome where its removed from the belt and stored in the dome which travels to the outside and is shortly followed by more and more, all collecting on the surface of the dome until discharged by a conductor or ionized by air.

thanks to [|http://www.magnet.fsu.edu/education/tutorials/magnetacademy/gmr/images/gmr-magwiresmall. jpg]

[|http://www.iop.org/activity/education/Teaching_Resources/Teaching%20Advanced%20Physics/Fields/Ima ges%20400/img_tb_4734.gif]

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[] for pictures, and the book for info.