Editing Negative-feedback amplifier (section)

===Load voltage and load current===
The gain derived above is the current gain at the collector of the output transistor. To relate this gain to the gain when voltage is the output of the amplifier, notice that the output voltage at the load ''R''<sub>L</sub> is related to the collector current by [[Ohm's law]] as ''v''<sub>L</sub> = ''i''<sub>C</sub> (''R''<sub>C2</sub> || ''R''<sub>L</sub>). Consequently, the transresistance gain ''v''<sub>L</sub> / ''i''<sub>S</sub> is found by multiplying the current gain by ''R''<sub>C2</sub> || ''R''<sub>L</sub>:

::<math> \frac {v_\mathrm{L}} {i_\mathrm{S}} = A_\mathrm{FB} (R_\mathrm{C2} \parallel R_\mathrm{L} ) \ . </math>

Similarly, if the output of the amplifier is taken to be the current in the load resistor ''R''<sub>L</sub>, [[current division]] determines the load current, and the gain is then:

::<math> \frac {i_\mathrm{L}} {i_\mathrm{S}} = A_\mathrm{FB} \frac {R_\mathrm{C2}} {R_\mathrm{C2} + R_\mathrm{L}} \ . </math>