Transconductance Transconductance Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Transconductance is very often denoted as a conductance, "g", with a subscript, m, for "mutual". It is defined as follows: For small signal alternating current, the definition is simpler: The SI unit, the siemens, with the symbol, S; 1 siemens = 1 ampere per volt replaced the old unit of conductance, having
2019 redefinition of SI base units the Avogadro constant, Brian Leonard of the University of Akron, writing in "Metrologia" proposed that the dalton (Da) be redefined such that , but that the unified atomic mass unit () retain its current definition based on the mass of C, ceasing to exactly equal to the dalton. This would result in the dalton and the atomic mass unit potentially differing from each other with a relative uncertainty of the order of 10. However, the draft of the ninth SI Brochure defines both the dalton (Da) and the unified atomic mass unit (u) as exactly 1/12 of the mass of