Three voltage amplifiers are in cascade as shown in Figure with various amplification factors. The 180 degree phase shift for negative feedback actually occurs in the basic amplifier itself.
(a) Determine the value of β such that the closed-loop voltage gain is Av f = Vo/Vs = -120.
(b) Using the results of part (a), determine the percent change in Av f if each individual amplifier gain decreases by 10 percent.
