Download Electric Fields and Potential

April 12, 2013
Electric Fields and
Potential
April 12, 2013
April 12, 2013
April 12, 2013
April 12, 2013
Electric Field
It is a vector quantity. It has both magnitude and
direction.
The direction of the field is always determined, by
convention, with a small, positive test charge.
Electric Field strength can be calculated using:
E = F/q and E = kq/d
2
http://phet.colorado.edu/en/simulation/efield
April 12, 2013
April 12, 2013
A fly accumulates 3.0 x 10-10C of positive charge as it flies
through the air. What is the magnitude and direction of the
electric field at a location 2.0 cm away from the fly?
April 12, 2013
Mr. Patel is photocopying lab sheets for his first period class. A
particle of toner carrying a charge of 4.0 x 10-9C in the copying
machine experiences an electric field of 1.2 x 106 N/C as it's
pulled toward the paper. What is the electric force acting on
the toner?
April 12, 2013
Gordon the night custodian dusts off a classroom globe with
a feather duster, causing the globe to acquire a charge of
-8.0 x 10-9C. What is the magnitude and direction of the
electric field at a point 0.4 m from the center of the
charged globe?
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April 12, 2013
Electric Field Lines
These are imaginary lines with arrow heads the show the direction
along which hypothetical positive charges would move.
Also called lines of force.
There are 3 rules to drawing electric field lines:
1. Field lines must begin on positive charges or at infinity and
must terminate on negative charges or at infinity.
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.
April 12, 2013
Electric Fields
April 12, 2013
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Online lab
http://phet.colorado.edu/en/simulation/charges-and-fields