Free · Physics models
Point-Charge Potential and Work
Find signed electrostatic potential for a point charge, a superposition of up to ten charges or a work-per-charge difference.
- Formula & worked example
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Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
Private by default
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Formula and method
A one-nanocoulomb charge one meter away has potential 8.987551788 volts in the captured vacuum constant approximation.
V=kq/r; homogeneous-medium k=8.987551788×10⁹/relative permittivity; ΔV=work/added charge.
Worked example
Enter these known values and leave the other values blank.
- Charge (q)
- 0.000000001 C
- Distance (r)
- 1000000 μm
- Electric potential (V)
- 0.000008988 × 10⁶ V
Assumptions and limitations
- Point charges are fixed in a homogeneous, linear medium; potential zero is at infinite distance. Charge and work can be signed.
- The captured Coulomb constant is rounded; measured permittivity uncertainty is not propagated. All ten charge slots remain in the sum, even when fewer controls are shown; clear unused nonzero slots.
- Finite-sized charges, dielectric interfaces, time-varying fields and self-energy are omitted.
- Clear the unknown numerical field before using a supported inverse; selection controls retain their captured branches.
Common questions
What assumptions matter for this model?
Point charges are fixed in a homogeneous, linear medium; potential zero is at infinite distance. Charge and work can be signed.
What does this model leave out?
Finite-sized charges, dielectric interfaces, time-varying fields and self-energy are omitted.
References
Model requirements: Point-charge separation must be positive. Relative permittivity must be positive. Authored accessible explanations preserve each captured diagram mode and its geometric relationships.