Download Electric Field Formulas and Units

Electric Field Formulas and Units
Charge
Distribution
Point
Diagram
Formula
( )
(
( )
Sphere
(
( )
Dipole
(along the
line of the
dipole
charges,
from center)
Point-like
outside, zero
inside
(
)
Point-like
outside,
decreases
linearly inside
(
)
( )
Infinite line
(at distance z
perpendicula
r to the line)
R. Gist
)
)
( )
Disk of
charge
(along axis
of symmetry,
distance z
from the
center)
Comments
( )
Spherical
shell
Finite line (at
distance z
perpendicula
r to the
center of the
line)
Ring of
charge
(along axis
of symmetry,
distance z
from the
center)
Far away
( )
( )
(
)(
( )
)
(
)
( )
[
(
)
]
Derived by
using
concentric
rings of
charge.
2/4/2013
Electric Field Formulas and Units
Infinite sheet
( )
E=constant
(uniform
field)
Independent
of distance.
Derived by
letting R go to
infinity in the
charged disk
formula
Parallel
infinite
sheets
( )
E=constant
(uniform
field)
Uniform field
between
sheets, zero
elsewhere
SI Base Units for electricity & magnetism: meter (m), kilogram (kg), second (s) and ampere (A)
Electro-Magnetic Quantities of Interest
Quantity
Commonly used
Variable
Q, q
F
Unit Name
Electric Field
E
(none)
Electric Flux
E
(none)
V, V, E
Volt
V
Capacitance
C
Farad
F
Current
I, i
Ampere
A
Resistance
R
Ohm

Magnetic Field
B
Tesla
T
Magnetic Flux
B
Weber
Inductance
L
Energy
Power
Charge
Force
Electric Potential, EMF
R. Gist
Coulomb
Newton
Unit
Symbol
C
N
In Terms of SI
Base Units
A·s
kg·m
s2
kg·m
A·s3
kg·m3
A·s3
kg·m2
A·s3
In Terms of Other
Common Units
V·F, J/V
C·V, C·m·T/s
N/C, V/m
V·m, N·m2/C
A·, H·A/s, C/F, Wb/s, J/C
A2  s4
kg·m 2
A
C/V
kg·m2
A 2 ·s 3
kg
A·s2
V/A
Wb
kg·m2
A·s2
V·s , T·m2
Henry
H
kg·m2
A 2 ·s 2
Wb/A, V·s/A, T·m2/A
U, E
Joule
J
kg·m2
s2
N·m, C2/F, H·A2, F·V2, C·V
P, P
Watt
W
kg·m2
s3
J/s, N·m/s, A·V, A2·
C/s, V/
Wb/m2, V·s/m2
2/4/2013