Unit systemCGS-EMU
Unit ofelectrical resistance
Named afterGeorg Ohm
In CGS base unitscm/s
1 abΩ in ...... corresponds to ...
   SI units10−9 Ω

The abohm is the derived unit of electrical resistance in the emu-cgs (centimeter-gram-second) system of units (emu stands for "electromagnetic units"). One abohm corresponds to 10−9 ohms in the SI system of units, which is a nanoohm.

The emu-cgs (or "electromagnetic cgs") units are one of several systems of electromagnetic units within the centimetre gram second system of units; others include esu-cgs, Gaussian units, and Heaviside–Lorentz units. In these other systems, the abohm is not one of the units.

When a current of one abampere (1 abA) flows through a resistance of 1 abohm, the resulting potential difference across the component is one abvolt (1 abV).

The name abohm was introduced by Kennelly in 1903 as a short name for the long name (absolute) electromagnetic cgs unit of resistance that was in use since the adoption of the cgs system in 1875.[1] The abohm was coherent with the emu-cgs system, in contrast to the ohm, the practical unit of resistance that had been adopted too in 1875.


  1. ^ A.E. Kennelly (1903) "Magnetic units and other subjects that might occupy attention at the next international electrical congress" 20th Annual Convention of the American Institute of Electrical Engineers, 1903