Source: https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/mechanism/

instrument mechanism / verified-clean

# Electric Potential (Point Charges) Calculator mechanism

The inspectable method record for Electric Potential (Point Charges) Calculator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The pair formulas are standard under the stated SI, vacuum, point-charge, and infinite-reference assumptions. The catalog claim is ambiguous because it says potential due to point charges plural while listing only the single-charge expression, and it does not specify how multiple-charge inputs are represented or whether U is for one pair or a complete charge system.

- V=kq/r is correct for the potential from one point charge, but the stated capability covers multiple point charges and requires V_total=Σ(kq_i/r_i). The spec does not define whether V means a single-source potential or the summed potential.

- U=kq1q2/r is the standard electrostatic potential energy for one pair of point charges, but total potential energy for multiple charges requires summing kq_iq_j/r_ij over all distinct pairs.

- The formulas assume a homogeneous vacuum or that k already includes the medium's permittivity; the medium is not specified.

## Units and conventions

- Use SI units: charge in coulombs, distance in meters, potential in volts, and energy in joules.

- For vacuum, use k=8.99×10^9 N·m²/C². In a material medium, k must be replaced by 1/(4πε) or an explicitly supplied equivalent.

- Charges are signed quantities; positive and negative signs determine the sign of V and U.

- Potential is referenced to zero at infinite distance.

- For U, r is the separation between the two charges, not each charge's distance from an observation point.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "k_N_m2_per_C2": 8990000000,
    "q_C": 0.000002,
    "r_m": 0.3,
    "q1_C": 0.000002,
    "q2_C": -0.000003,
    "pair_distance_m": 0.5
  },
  "expected_outputs": {
    "V_V": 59933.333333333336,
    "U_J": -0.10788
  },
  "working": "V=(8.99×10^9)(2×10^-6)/0.30=(17980)/0.30=59933.333333333336 V. U=(8.99×10^9)(2×10^-6)(-3×10^-6)/0.50=(8.99×10^9)(-6×10^-12)/0.50=(-0.05394)/0.50=-0.10788 J."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The formula has an undefined zero-distance case, so the instrument must reject r=0 rather than perform plain division. The specification also leaves distance-sign conventions unstated and has no actual piecewise formula branch.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/electric-potential-point-charges-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`