What is Electrostatic field? — Physics

Definition 26.4 University Physics — Year 1 · Chapter 26 — Electrostatics: Field and Gauss’s Law

A distribution of charges at rest creates at every point $M$ of space an electric field $\vect E(M)$ , defined by the force it exerts on a test charge $q$ placed at $M$ : $\vect F = q\vect E(M)$ ( $\mathrm{V}/\mathrm{m}$ $=$ $\mathrm{N}/\mathrm{C}$ ). A point charge $q_1$ at $O$ creates

\vect E(M) = \frac{q_1}{4\pi\varepsilon_0 r^2}\,\vect e_r , \qquad r = OM ,

radial, outward for $q_1 > 0$ ; a distribution creates the vector sum of the fields of its elements. A field line is a curve tangent at each point to $\vect E$ , oriented along it.

Field lines of two opposite charges (left) and of two equal positive charges (right). Lines start on + and end on - or at infinity; on the right they repel each other and the field vanishes at the midpoint, where no line passes. — Field lines of two opposite charges (left) and of two equal positive charges (right). Lines start on $+$ and end on $-$ or at infinity; on the right they repel each other and the field vanishes at the midpoint, where no line passes.

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