3D Electrostatics Field Explorer

Place point charges and drag the green test charge. Watch the purple electric field $\vec{E}$ and the red force $\vec{F}=q\vec{E}$ update in 3D.

Controls

+2.0
+1.0
0.50
10

Readings at Test Charge

|E| 0 N/C
|F| 0 N
Direction of E —
Ex, Ey, Ez 0, 0, 0

Legend

  • Positive charge / Force F
  • Negative charge
  • Electric Field E
  • Test charge q₀
+ / F − E q₀
Drag q₀ or charges • Empty space rotates • Scroll zooms

HKDSE Formula Focus

  • $E = kQ / r^2$ with $k = 8.99\times 10^9$
  • $F = qE$ force on the test charge
  • Net $\vec{E}$ is the vector sum of all source charges.
  • Like charges repel; unlike charges attract.

Coulomb Field

$\vec{E} = \dfrac{1}{4\pi\varepsilon_0}\dfrac{Q}{r^2}\hat{r}$

Field lines leave positive charges and enter negative charges. The red arrow is F; the purple arrow is E at q₀.