An Electric Field is a map of the force that a “test charge” would feel at any point in space. It allows us to describe the influence of a charge without needing a second object present.

Field Lines

  • Lines point away from positive charges.
  • Lines point toward negative charges.
  • The density of lines indicates the strength of the field.

Mathematical Definition

\[\vec{E} = \frac{\vec{F_e}}{q_0}\]

The units for Electric Field are Newtons per Coulomb (N/C).

💡 Quick Concept Check:

If an electric field line starts on one charge and ends on another, what can you say about those two charges?

Click to Reveal Answer
They must be **opposite charges**. Field lines always originate on positive charges and terminate on negative charges.
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