The field around a point charge follows E = kQ/r² — pointing away from a positive charge, toward a negative one, and falling off as 1/r². Drag the probe (or use the slider) to read the field and the force it would put on a 1 nC test charge.
Field strength E = kQ/r²
4.50 × 103 N/C
outward (repulsive)
Force on a 1 nC test charge F = qE
4.50 × 10-6 N
Source charge Q+5.0 nC
Probe distance r0.100 m
k = 8.99 × 109 N·m²/C² · test charge q = 1 nC · drag the probe in the canvas to move it