The Physics
Hypertextbook
Opus in profectus

Electric Field

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Discussion

introduction

Some text and some diagrams. The electric field as a vector field.

And more diagrams. The electric field as field lines.

And maybe some mathematics. In classical field theory, the strength of the field at a point is the normalized value of the field. In other words…

field =  force
quantity

For electricity, this becomes…

E = FE
q

There is no special name for its unit, nor does it reduce to anything simpler.


N  =  kg m/s2  =  kg m
C A s A s3

We will see later that this is equivalent to…


N  =  V
C m

Some values…

For point charges…

E =  1   q   or E = k  q  
4πε0   r2 r2

For multiple point charges…

E =  1  ∑  dq   or E = k ∑  dq  
4πε0 r2 r2

For continuous charge distributions…

E =  1
dq   or E = k
dq  
4πε0 r2 r2