ch33_awks

=Chapter 33- Electric Fields and Potential=

A gravitational field exists around any object with mass and will exert a force on any other mass in that field, however an electric field around any charged object that will exert a force on any other charged object placed in that field.
 * Electric Fields:**

An electric field around one or more charges can be represented by drawing lines to show the strength and direction of the field. There are three main rules to follow when drawing a field line: 1.Field lines must begin on postive charges or at inifinity and must terminate on the negative charges or at inifinity. 2.The number of lines drawn leaving a positive charge or approaching a negative charge is proportional to the magnitude of the charge. 3.No two field lines from the same field can cross each other.
 * Electric Field Lines:**


 * Different types of field lines:**

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 * A single positive charge and A single negative charge**

Equal positive and negative charges** [|**http://facstaff.gpc.edu/~pgore/PhysicalScience/electric-charge.html**] Equal positive charges** [|**http://electron9.phys.utk.edu/phys136d/modules/m4/efield.htm**]
 * [[image:http://facstaff.gpc.edu/~pgore/PhysicalScience/Martin/e-field_pos_neg.jpg width="216" height="165"]]
 * [[image:http://electron9.phys.utk.edu/phys136d/modules/m4/images/Image990.gif width="211" height="200"]]

Static charges on a conductor distribute themselves as far away from each other as possible causing charges to accumulate on the outside surface of the conductor with none of the unbalance charges in the center. This also causes the largest charge of accumulation at the smallest part of the of the curvature( the more pointed a part of the object is,more of charge will accumulate).
 * Electric Shielding:**

Potential energy exists anywhere work has been done to put a new object into a new position. The work done to move the object in the electric field will be stored in the object as electric potential energy and can be recovered by restoringt the object to its initial position.
 * Electric Potential Energy:**

To find the electric potential energy requires that the object moved be known. Sometimes its useful to know how much the electric potential is before you know the object's charge. Electric potential is defined as electric potential energy/charge. Electric potential is measured in joules of energy per coulomb of charge. This quantity is called a volt. Due to the unites used it is often refered as voltage.
 * Electric Potential:**

A capacitor is known as the electrical energy that can be stored in devices. It has two plates one which takes in positive charges and another which takes in negative charges. By placing the plates near each other with an insulator between them, the plates' opposite charges will attract towards eachother. The Van de Graaf generator is used for building a very high voltage charge on a metal sphere which can then be used for various purposes. The generator works by causing a small charge to be deposited on a moving belt in the base. Next, The belt carries the charge to the top sphere where it is removed from the belt on the inside of the sphere. The charge travels to the surface of the sphere leaving the generator ready to move more charge off the belt.
 * Electric Energy Storage:**
 * The Van de Graaf Generator:**