Divergence%20and%20Curl%20of%20Electrostatic%20Fields

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Divergence and Curl of Electrostatic Fields
Field of a point charge
arrows
field lines
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Bits of thread in oil align with the field
lines.
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Construction principle Field lines start at q
and end at q. The number of lines is
proportional to q. If the total charge is
different from 0, there will be lines going to
or coming from infinity. Field lines never
cross. The field lines point in radial direction
near point charges.
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Divergence of E (Gausss Law)
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Application of Gausss law (integral form)
The direction of the field is known, and it is
constant on the Gaussian surface
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Example 2.2
What is the field outside the uniformly charged
sphere?
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Example 2.3
Field inside a long cylinder with charge density
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Example 2.4
Infinite plate with uniform surface charge density
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Example 2.5
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Field Lines and Flux
Flux through a surface
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Conservation of flux
Flux tube
The flux (number of field/stream lines) through
the different cross sections of the flux tube is
constant.
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Curl of E
General properties
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Laws of electrostatics