Equation Summary for Electric Fields

 
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For All Force Fields
Units
Force
2nd >
F=Eq
N
Electric Field Strength

E=F/q

N/C
Work (electric potential energy)
5th>
W=EEP=qDV
J
Electric Potential

DV=EEP/q

(by definition)

V
 

Uniform Electric Fields

note 3

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Point Charge Electric Fields
Force
 

F=DVq/d

see note 1

1st >

F=kq1q2/r**2

or

F=(1/4peo)q1q2/r**2

N
Electric Field Strength
5th>
E=V/d
3rd >
E=kq/r**2
N/C
Work (electric potential energy)
4th >
W=DEEP

=Eqd

see note 1

EEP=kq1q2/r

see note 1,2

J
Electric Potential
5th>
V=Ed
6th>

V=kq/r

or

V=(1/4peo)q/r

V

note 1: not in IB Data Booklet

note 2: this equation not directly needed in IB
note 3: Although these are stated to be true for uniform fields they can be true for any field if the limit of the variables is infinitely small. For example E=V/d could be expressed in any field as E=DV/Dd where D - "delta" means change in. In this example we would say that the electric field strength is the gradient of the potential.

comparison to gravitational fields

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