<Dd> V out = R 1 + R 2 R 1 V in = 1 β V in (\ displaystyle V_ (\ text (out)) = (\ frac (R_ (\ text (1)) + R_ (\ text (2))) (R_ (\ text (1)))) V_ (\ text (in)) \! = (\ frac (1) (\ beta)) V_ (\ text (in)) \,). </Dd> <P> A real op - amp has a high but finite gain A at low frequencies, decreasing gradually at higher frequencies . In addition, it exhibits a finite input impedance and a non-zero output impedance . Although practical op - amps are not ideal, the model of an ideal op - amp often suffices to understand circuit operation at low enough frequencies . As discussed in the previous section, the feedback circuit stabilizes the closed - loop gain and desensitizes the output to fluctuations generated inside the amplifier itself . </P> <P> An example of the use of negative feedback control is the ballcock control of water level (see diagram). In modern engineering, negative feedback loops are found in fuel injection systems and carburettors . Similar control mechanisms are used in heating and cooling systems, such as those involving air conditioners, refrigerators, or freezers . </P> <P> Some biological systems exhibit negative feedback such as the baroreflex in blood pressure regulation and erythropoiesis . Many biological process (e.g., in the human anatomy) use negative feedback . Examples of this are numerous, from the regulating of body temperature, to the regulating of blood glucose levels . The disruption of feedback loops can lead to undesirable results: in the case of blood glucose levels, if negative feedback fails, the glucose levels in the blood may begin to rise dramatically, thus resulting in diabetes . </P>

Explain the effects of a disruption in a feedback mechanism