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Electric field and Potential. Tutoring schedule. Recall the Electric Field?. Recall the Electric Field?. Field lines?. Useful conceptualization of the electric field. Field Lines:. Field Lines:. A field line always Begins on a positive charge (or infinity)
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Electric field and Potential Tutoring schedule
Field lines? Useful conceptualization of the electric field.
A field line always • Begins on a positive charge (or infinity) • Ends on a negative charge (or infinity)
Field Lines: Big step!
Field Lines: Big step!
Field Lines: Big steps give rough idea of field lines
Field Lines: Lot’s of little steps more accurate
A any point along a field line, the electric field points in the direction tangent to the line. But the field line by itself tells us nothing about the magnitude of E
Note: color Scheme is backward
Note: Electric field lines are not the path a test particle would follow Hockey demo again !! http://phet.colorado.edu/en/simulation/electric-hockey All they do is indicate the direction of the electric field (at any given point). But, you can get a little more info too …
Magnitude of electric field Is related to the spacing of adjacent lines The closer the spacing, the stronger the field
Electric Fields and conductors: Conductor ↔ charges free to move
Electric Fields and conductors: Conductor ↔ charges free to move + + + − + − + − + − − −
How it works: Eventually …..
How it works: The mobile charges rearrange themselves until everywhere in the conductor
So in the static case : • Electric field is zero inside a conductor • No Net charge on the inside of a conductor • free charge must all be on surface • Electric field just outside the conductor must be perpendicular to the surface! • Magnitude of this Electric field is related to the density of charge on the surface at that point. (Gauss’s Law again)