Abampere Unit | All you need to know
The abampere (symbol: aA or abA) is a unit of electric current. It is part of the centimetre–gram–second (CGS) system of units, specifically the electromagnetic (EMU) branch. The prefix "ab" stands for "absolute," which was used to distinguish CGS units from the "practical" units that became the SI system we use today.
While not used in common electronics, the abampere is important in physics and understanding the history of electrical measurements. The most important thing to know is its relationship to the standard unit, the Ampere.
- 1 Abampere (aA) = 10 Amperes (A)
Where Does the Abampere Come From?
Before the modern SI system (which uses meters, kilograms, and seconds) was standardized, many scientists used the CGS system (centimetres, grams, and seconds). The CGS system had different branches for electricity. The abampere belongs to the CGS-EMU (electromagnetic unit) system, which defines electrical units based on the magnetic forces they create.
This is the opposite of the SI system, which defines the Ampere first and derives magnetic units from it.
The Scientific Definition of an Abampere
The formal definition of the abampere is based on magnetic force. It is defined as:
An abampere is the constant current which, if maintained in two straight, parallel conductors of infinite length and negligible cross-section, placed 1 centimetre apart in a vacuum, would produce a force between them of 2 dynes per centimetre of length.
This definition directly links current to the CGS base units of force (dyne) and distance (centimetre).
Abampere to Ampere: The Key Conversion
For all practical purposes, the most useful piece of information is the conversion to Amperes (A), the standard SI unit for electric current.
The relationship is very simple:
- 1 Abampere (aA) = 10 Amperes (A)
- 1 Ampere (A) = 0.1 Abamperes (aA)
This means the abampere is a much larger unit than the ampere. For example, a standard household circuit breaker rated for 15 Amperes would be rated for only 1.5 Abamperes.
Who Still Uses the Abampere?
Today, the abampere is considered a legacy unit. You will almost never find it used in modern engineering, electronics, or by electricians. The Ampere is the universal standard for all practical applications.
However, the abampere and other CGS-EMU units are still sometimes used in specific, advanced fields of physics, such as theoretical electromagnetism and astrophysics. They are also important for anyone reading older scientific papers or textbooks.
Related CGS Units
The abampere is the base unit for other electromagnetic CGS units, such as:
- Abcoulomb (aC): The unit of charge (1 aC = 10 Coulombs)
- Abvolt (aV): The unit of voltage (1 aV = 10-8 Volts)
- Abohm (aΩ): The unit of resistance (1 aΩ = 10-9 Ohms)
The Key Takeaway
The abampere is a CGS unit of current that is 10 times larger than the Ampere. While it's largely been replaced by the SI system, it remains a key part of the history of physics and is still found in some technical fields.
Need to convert abamperes to amperes or any other current unit? Find all the powerful and easy-to-use conversion tools you need right here at changeunit.com!