Chemical Engineering - Process Control and Instrumentation
Exercise :: Process Control and Instrumentation - Section 4
1.
The time constant of a unity gain, first order plus time delay process is 5 min. If the phase lag at a frequency of 0.2 rad/min is 60°, then the dead time (in minutes) is
Answer: Option A
Explanation:
2.
Which of the following does not figure in the list of seven substances selected for international temperature scale ?
A. Ice (F.P) and steam (B.P) B. Oxygen and sulphur (B.P) C. Antimony and silver (F.P) D. Zinc (B.P) and mercury (F.P)
Answer: Option D
Explanation:
3.
A constant volume gas thermometer employing __________ is used to measure sub-zero (i.e., < 0° C) temperature.
A. helium B. hydrogen C. nitrogen D. none of these
Answer: Option A
Explanation:
4.
pH meter has
A. one cell B. two cells C. three cells D. no cell
Answer: Option B
Explanation:
5.
Routh test
A. criterion provides information about the actual location of roots. B. cannot be used to test the stability of a control system containing transportation lag. C. criterion is not applicable to systems with polynomial characteristic equation. D. can not determine as to how many roots of the characteristics equation have positive real roots.
Answer: Option B
Explanation:
