<quizlib id=„quiz1“ rightanswers=„'a3'“ submit=„check answers“>

  <question title="How is the output resistance of an amplifier defined?" type="checkbox">

$R_O = \Delta U_{\rm I} / \Delta I_{\rm O}$| $R_O = U_{\rm I} / I_{\rm O}$| $R_O = \Delta U_{\rm O} / \Delta I_{\rm O}$| $R_O = -\Delta U_{\rm O} / \Delta I_{\rm O}$| $R_O = U_{\rm O} / I_{\rm O}$ </question></quizlib>