1. The main function of PI cascade compensator is improving a system's ( )
A. Stability B. Steady-state performance
C. Stability and steady-state performance D. Stability and response speed
2. The main function of PD cascade compensator is improving a system's ( )
A. Stability B. Steady-state performance
C. Disturbance rejection D. Steady-state performance and response speed
3. Which of the following compensation elements is PI compensation ( )
A. 
B. 
C. 
D. 
B. C. D.
4. Which of the following compensation elements is phase lag compensation ( )
A. 
B. 
C. 
D. 
B. C. D. 5.Which of the following statements about phase lead compensation is correct ( )
A. Phase lead compensation increases the slope of magnitude plot at 
B. Phase lead compensation is not suitable for the case that the slope of magnitude plot at is steep
is steepC. Phase lead compensation is suitable for the case that the slope of phase plot at is steep
is steepD. If the desired bandwidth is more narrow than that of the uncompensated system, then phase lead compensation should be used
6. When a phase lag compensator is added to a system, then ( )
A. Steady-state performance of the system is improved
B. The break frequency of magnitude is increased
C. The rise time of the system is decreased
D. The resonance peak value of the system is increased
正确的答案是：B、D、C、A、B、A
