ab-

   a prefix indicating that an electrical unit is part of the CGS absolute electromagnetic system. These units are also indicated by the notation emu (as in "volt emu"). Although these units are defined naturally as part of the CGS system, all of them except the abampere and abcoulomb are either much too large or much too small for most applications. They have been replaced almost completely by the corresponding SI units. Following are the SI equivalents for each of the "ab" units:

   Electric current: 1 abampere = 10 amperes

   Electric charge: 1 abcoulomb = 10 coulombs

   Capacitance: 1 abfarad = 10⁹ farads = 1 gigafarad

   Inductance: 1 abhenry = 10^-9 henry = 1 nanohenry

   Resistance: 1 abohm = 10^-9 ohm = 1 nanoohm

   Conductance: 1 abmho = 10⁹ siemens

   Magnetic flux density: 1 abtesla = 10^-4 tesla = 1 gauss

   Potential: 1 abvolt = 10^-8 volt = 10 nanovolts

   Power: 1 abwatt = 10^-7 watt = 0.1 microwatt

   Magnetic flux: 1 abweber = 10^-8 weber = 1 maxwell.