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________________?
Correct answer: A. 5π/12
- A. 5π/12
- B. π/6
- C. π/12
- D. π/3
Explanation
The total phase lag is tan⁻¹(ωτ)+ωθ. With ωτ=0.2×5=1, the first-order lag is 45°, leaving 15° or π/12 rad for the delay, so θ=(π/12)/0.2=5π/12 min.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
Practise Process Control and Instrumentation
254 free Process Control and Instrumentation MCQs from Chemical Engineering, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemical Engineering questions like this
Chemical Engineering is on this paper prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for it.
More Process Control and Instrumentation questions
Dead zone is the__________________?
All the thermocouples used for temperature measurement use dissimilar metal ________________?
Phase margin is equal to_______________?
The transfer function for a P-D controller is________________?
Water is entering a storage tank at a temperature T0 and flow rate Q0 and leaving at a flow rate Q and temperature T. There are negligible heat losses in the tank. The area of cross-section of the tank is A0. The model that describes the dynamic variation of temperature of water in the tank with time is given as________________?
The root locus plot of the roots of the characteristics equation of a closed loop system having the open loop transfer function K (s + 1)/[2 (2s + 1) (3s + 1)] will have a definite number of loci for variation of K from 0 to ∞. The number of loci is_______________?