- For an amplifying device, such as a transistor or an electron tube, the ratio of the change in output current to the change in input current. For example, in a tube, it is the ratio of the change in plate current to the change in grid voltage, with the plate voltage held constant. Usually expressed in multiples of siemens or mhos.
- For a component, circuit, or device, the ratio of the output current to the input current.
Not what you were looking for?