$word_{count}$: 270

The electric field E at a point is the force experienced by a unit positive test charge placed at that point: E = $\frac{F}{q_0}$ (with $q_0$ -> 0 to avoid disturbing the source). SI unit: N/C = $\frac{V}{m}$. Dimensions: [M L T^(-3) A^(-1)]. The field is a vector quantity existing at every point in space, created by source charges.

For a point charge Q: E = $\frac{kQ}{r}$^2, directed radially outward for positive Q and inward for negative Q. The field mediates the force — charge Q creates a field, and charge q in that field experiences F = qE. This "field" view replaces action-at-a-distance.

Electric field lines are visual representations. They start on positive charges, end on negative charges, never cross (uniqueness of E direction), never form closed loops (conservative field), and their density indicates field strength. Lines are perpendicular to equipotential surfaces and to conductor surfaces in equilibrium.

The field satisfies superposition: $E_{net}$ = vector sum of individual fields. For two equal positive charges, E = 0 at the midpoint. For unequal like charges q1 and q2 (q1 > q2) at distance d, the zero-field point is between them at distance d*sqrt$\frac{q1}{(sqrt(q1)}$+sqrt(q2)) from q1 (closer to the smaller charge). For opposite charges, the zero-field point is outside, beyond the smaller magnitude charge.

Key JEE application: a charge in a uniform field E undergoes constant acceleration a = $\frac{qE}{m}$, producing straight-line or parabolic motion depending on initial velocity direction.