This page documents an OPTIMADE Unit Definition. See https://schemas.optimade.org/ for more information.

**ID: https://schemas.optimade.org/defs/v1.2/units/si/1960/named/ohm**

`ohm`

**Unit name:** ohm

**Latin symbol:** ohm

**Display symbol:** Ω

**Description:** A derived SI unit for electrical resistance equal to kg·m²·s⁻³·A⁻² in the 1960 SI base units.

"The ohm is the electrical resistance that exists between two points of a conductor when a constant potential difference of one volt, applied between these two points, produces a current of one ampere in the conductor, provided that the conductor is not the seat of any electromotive force." [9th CGPM meeting in 1946]

**Resources:**

- Definition at the 9th CGPM meeting (1948)
- Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.
- Wikipedia article describing the unit

**JSON definition:**

```
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/named/ohm",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/physical_unit_definition.json",
"title": "ohm",
"symbol": "ohm",
"display-symbol": "\u03a9",
"description": "A derived SI unit for electrical resistance equal to kg\u00b7m\u00b2\u00b7s\u207b\u00b3\u00b7A\u207b\u00b2 in the 1960 SI base units.\n\n\"The ohm is the electrical resistance that exists between two points of a conductor when a constant potential difference of one volt, applied between these two points, produces a current of one ampere in the conductor, provided that the conductor is not the seat of any electromotive force.\" [9th CGPM meeting in 1946]",
"resources": [
{
"relation": "Definition at the 9th CGPM meeting (1948)",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
},
{
"relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
},
{
"relation": "Wikipedia article describing the unit",
"resource-id": "https://en.wikipedia.org/wiki/Ohm"
}
],
"defining-relation": {
"base-units": [
{
"symbol": "A",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/ampere"
},
{
"symbol": "kg",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
},
{
"symbol": "m",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
},
{
"symbol": "s",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/second"
}
],
"base-units-expression": "A^-2*kg*m^2*s^-3"
},
"standard": {
"name": "si",
"year": 1960,
"category": "named",
"symbol": "ohm"
},
"x-optimade-definition": {
"label": "ohm_si_1960_named",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "ohm"
}
}
```