Abohm

{{Short description|Unit of electrical resistance in emu-cgs system}}

{{Infobox

| above = abohm

| label2 = Unit system | data2 = CGS-EMU

| label3 = Unit of | data3 = electrical resistance

| label4 = Symbol | data4 = abΩ

| label5 = Named after | data5 = Georg Ohm

| label6 = In CGS base units | data6 = cm/s

| header7 = Conversions

| data8 = {{val|1|u=abΩ}} in ...... corresponds to ...

| label9 =    SI units | data9 = {{val|e=-9|u=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.A.E. Kennelly (1903) [https://dokumen.tips/documents/magnetic-units-and-other-subjects-that-might-occupy-attention-at-the-next-international.html "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 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.