The ohm (symbol: Ω, the uppercase Greek letter omega) is the unit of electrical resistance in the International System of Units (SI). It is named after German physicist Georg Ohm (1789–1854). Various empirically derived standard units for electrical resistance were developed in connection with early telegraphy practice, and the British Association for the Advancement of Science proposed a unit derived from existing units of mass, length and time, and of a convenient scale for practical work as early as 1861.
AI overview
An ohm is the standard unit used to measure electrical resistance, which is the opposition that a material presents to the flow of electric current. It matters because it provides a common way to quantify and compare how much different materials and components resist electricity, making it essential for designing and understanding electrical systems.
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Key facts
- Unit.symbol
- Ω
- Unit.name
- ohm
- Unit.image
- 240px
- Unit.caption
- A laboratory one-ohm standard resistor,
- Unit.standard
- SI
- Unit.quantity
- electrical resistance
- Unit.namedafter
- Georg Ohm
- Unit.units1
- SI base units
- Unit.inunits1
- kg⋅m2⋅s−3⋅A−2
via Wikipedia infobox
Article
10 sectionsContents
- Definition
- Relation to conductance
- Power as a function of resistance
- History
- Historical units of resistance
- Realization of standards
- Symbol
- See also
- Notes and references
- External links
The ohm (symbol: Ω, the uppercase Greek letter omega) is the unit of electrical resistance in the International System of Units (SI). It is named after German physicist Georg Ohm (1789–1854). Various empirically derived standard units for electrical resistance were developed in connection with early telegraphy practice, and the British Association for the Advancement of Science proposed a unit derived from existing units of mass, length and time, and of a convenient scale for practical work as early as 1861.
Following the 2019 revision of the SI, in which the ampere and the kilogram were redefined in terms of fundamental constants, the ohm is now also defined as an exact value in terms of these constants.