Q3 a) Write down expressions for the open-loop, loop and closed-loop gains of the system shown in FIGURE 1 in terms of the stage gains
A,B,C
. FIG. 1 (b) The table below gives the magnitude and phase angle of the stage gains of the system represented by FIGURE 1. i) Determine if the system is stable. ii) Determine the new value of controller gain that will cause the system output to oscillate with constant amplitude. \table[[,Magnitude of gain,Phase angle],[Controller,
A
,0.5,
13\deg