Abcoulomb

n The abcouloumb, the emu of charge, is defined as the charge which passes a given surface in 1 s if a steady current of 1 abampere flows across the surface. Its dimensions are, therefore, cm^0.5 gm^0.5 which differ from the dimensions of the statcoulomb by a factor which has the dimensions of speed. This relationship is connected with the fact that the ratio 2K _e /K _m must have the value of the square of the speed of light in any consistent system of units. It follows further that

$$1\,{\rm abcouloumb} \, = \,2.99793 \times {10^{10}}\,{\rm statcoulomb},$$

the speed of light in vacuo being (2.99793 ± 0.000003) × 10¹⁰ cm/s (Weast RC (ed) Handbook of chemistry and physics, 52nd edn. CRC Press, Boca Raton, FL).