Charge & Electric Fields
A source charge changes the space around it. The electric field tells what force a positive test charge would experience at each location.
What exists between two charged objects before the second object even arrives?
The electric field belongs to the source configuration and space around it. A test charge samples that field. Changing the test charge changes the force, but it does not redefine the pre-existing field in this model.
The field comes from the source charge . The force also depends on the test charge .
Change the source, distance, and test charge independently.
Electric field points in the direction a positive test charge would accelerate: away from positive sources and toward negative sources.
The source field stays the same. Since F = qE, a negative q makes the force point opposite the electric field.
For a point charge, doubling the distance reduces the field magnitude to one quarter. The inverse-square structure spreads influence over growing spherical area.
At each point in space, E tells the force-per-positive-charge that a small test charge would experience there.
With several source charges, add their electric-field vectors. Each source contributes independently to the total field.
The same electric field can push positive and negative charges in opposite directions and with different magnitudes.