Run the VBA simulator and perform a setpoint change step test of 10% (closed loop) for the heat exchanger (HEATEX). Choose PI control with a Kc of 100 and tauI of 10. What does the controlled variable do over time?

a. It increases with mild overshoot, resulting in oscillations that die out quickly. b. The system is overdamped (there are no oscillations). c. The system is unstable. d. It results in ringing

Run a setpoint change step test (closed loop) of 1% for the CSTR. With PI control, set Kc = 1000. Which of the following values of tauI give you a decay ratio closest to 0.25?

a. 0.08

b. 0.2

c. 0.5

d. 1