______________ controller has the maximum stabilising time?

Related Mcqs:

1. An ideal PID controller has the transfer function [1 + (1/0.55) + 0.25]. The frequency at which the magnitude ratio of the controller is 1, is________________?

   A. 0.5/0.2
   B. 0.2/0.5
   C. 0.2 × 0.5
   D. 1/√(0.2 × 0.5)

2. In a closed loop system, the process to be controlled is an integrating process with transfer function 1/2s. The controller proposed to be used in an integral controller with transfer function 1/T1s. When a step change in set point is applied to such a closed loop system, the controlled variable will exhibit__________________?

   A. Overdamped response
   B. Underdamped response
   C. Undamped response
   D. Unstable response

3. Stabilising time for the controllers is the time required for the response to reach _____________ percent of its ultimate value?

   A. 63.2
   B. 87.5
   C. 95
   D. 100

4. Flapper nozzle is used in a/an ______________ controller?

   A. Electronic
   B. Hydraulic
   C. Pneumatic
   D. None of these

5. Feed forward controller accounts for the ______________ changes?

   A. Set point
   B. Load
   C. Both A. & B.
   D. Neither A. nor B.

6. The transfer function for an ideal proportional plus reset controller (reset time T) is_______________?

   A. Kc[1 + (1/TS)]
   B. Kc(1 + TS)
   C. Kc/(1 + TS)
   D. Kc/[1 + (s/T)]

7. Suppose that the gain, time constant and dead time of a process with the following transfer function: Gc(s) = 10 exp( – 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as________________?

   A. 8, 0.6, 0.08
   B. 12, 0.6, 0.12
   C. 8, 0.6, 0.12
   D. 12, 0.4, 0.08

8. A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if________________?

   A. Kc is reduced
   B. Kc is increased
   C. Integral control action is introduced
   D. Derivative control action is introduced

9. Which of following error integral is considered as the best criterion in controller settings ?

   A. ∫0 ∞ |e| dt
   B. ∫0 ∞ |e2| dt
   C. ∫0 ∞ e2 dt
   D. None of these

10. If response of a control system is to be free of offset and oscillation, the most suitable controller is_________________?

    A. Proportional controller
    B. Proportional-derivative (PD) controller
    C. Proportional-integral (PI) controller
    D. Proportional integral-derivative (PID) controller