Solve electric potential using point charges or fields. See steps, units, and sign conventions clearly. Download CSV or PDF, then reuse your inputs later.
| Scenario | Inputs | Computed output |
|---|---|---|
| Point charge | q = 2 µC, r = 0.50 m | V ≈ 3.595e+04 V |
| Two charges | (q₁= 1 µC, r₁=0.40 m), (q₂=-0.5 µC, r₂=0.20 m) | V ≈ -1.123e+04 V |
| Uniform field | E = 3 kV/m, d = 0.20 m, θ = 0° | ΔV = -600 V |
Electric potential (V) expresses energy change per unit charge, measured in volts (J/C). In this calculator, a 2 µC source at 0.50 m produces about 3.60×104 V in vacuum/air using k≈8.99×109. Scaling is linear: doubling q doubles V, while doubling r halves V.
The point-charge equation V=kq/r is highly distance-sensitive near the source. If q=1 µC, V is ~8.99×103 V at 1 m, but rises to ~8.99×104 V at 0.10 m. This is why small measurement errors in r can dominate the final value in short-range problems.
When several charges influence one point, potentials add as scalars. For (q1=1 µC, r1=0.40 m) and (q2=−0.5 µC, r2=0.20 m), the contributions are +2.25×104 V and −2.25×104 V, giving a total near zero. The bar chart shows each contribution clearly before summing.
In a uniform field, the calculator uses ΔV=−E·d·cos(θ). With E=3 kV/m and d=0.20 m, moving parallel to E (θ=0°) yields −600 V, while moving opposite (θ=180°) yields +600 V. The graph sweeps θ from 0° to 180° to visualize sign changes.
Real problems often mix units: charges in nC or µC and distances in cm or mm. This tool converts everything to C and m internally, then reports results in volts. For example, 500 nC equals 5.00×10−7 C, and 25 cm equals 0.25 m. Consistent units keep results comparable across modes.
Negative potential typically indicates a negative source charge or motion with the field direction in ΔV calculations. Distances must be positive because r appears in the denominator. For materials other than air, replace k with 1/(4πϵ) using the medium’s permittivity, which reduces potential by the relative permittivity factor.
It returns electric potential V for point or multiple charges, or potential difference ΔV for a uniform field, all in volts with unit conversions applied.
Potential is proportional to charge sign. A negative charge gives negative V. In a uniform field, ΔV becomes negative when displacement is along the field direction.
Yes. Select the appropriate units. The tool converts to meters and coulombs internally, then computes volts and displays consistent scientific formatting when needed.
Point-charge mode plots V versus r around your input distance. Multi-charge mode shows each charge’s voltage contribution. Field mode plots ΔV versus θ from 0° to 180°.
The default uses vacuum/air. For dielectrics, the effective constant becomes k/εr. You can approximate by dividing the displayed V or ΔV by the relative permittivity.
Distance must be positive because the model contains division by r. A zero or negative value is non-physical here and would cause infinite or invalid outputs.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.