Documents

CHEMICAL ENGINEERING OBJECTIVE TYPE QUESTIONS instrumentation and process control[1].pdf

Categories
Published
of 15
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Description
Page 1 CHEMICAL ENGINEERING OBJECTIVE TYPE QUESTIONS: A COMPILATION DR. LEONARDO C. MEDINA, JR. DEAN, COLLEGE OF ENGINEERING LYCEUM OF THE PHILIPPINES UNIVERSITY INSTRUMENTATION AND PROCESS CONTROL Page 2 1. What is the Laplace transform of sin t ? (a) __1__ (b) __s_____ s² + 1 1 + s² (c) __1 (d) __s_____ s² - 1
Transcript
  Page 1 CHEMICAL ENGINEERING OBJECTIVE TYPE QUESTIONS: A COMPILATION DR. LEONARDO C. MEDINA, JR. DEAN, COLLEGE OF ENGINEERING LYCEUM OF THE PHILIPPINES UNIVERSITY INSTRUMENTATION AND PROCESS CONTROL  Page 2 1. What is the Laplace transform of sin t   ? (a) __1__ (b) __s_____ s² + 1  1 + s² (c) __1 (d) __s_____ s² - 1 s² - 1 2. The transfer function of the first order system is (a) __1 (b) _1_ T  s + 1 T  s (c) ___s__ (d) 1/s T  s + 1 3. Pick out the first order system from among the following (a) damped vibrator (b) mercury in glass thermometer kept in boiling water (c) interacting system of two tanks in series (d) non-interacting system of two tanks in series 4. Response of a system to a sinusoidal input called (a) impulse response (b) unit step response (c) frequency response  (d) step response 5. What is the ratio of output amplitude to input amplitude for a sinusoidal forcing function in a first order system ? (a) 1 (b) > 1 (c) < 1 (d) none of these 6. Phase lag of the sinusoidal response of a first order system is (a) 120º  (b) 30º (c) 180º (d) 90º 7. Conversion formula for converting amplitude ratio (  AR  ) into decibels is (a) Decibel=20 log10 (  AR  )  (b) Decibel=20 log e(  AR  ) (c) Decibel=20 log10 (  AR  )0.5 (d) Decibel = log10 (AR) 8. “A control system is unstable if the open loop frequency response exhibits an amplitude ratio exceeding unity at the cross- over frequency.” This is   (a) Bode stability criterion  (b) Nyquist criterion (c) Routh stability criterion (d) both b and c  Page 3 9. Typical specifications for design stipulates the gain margin and phase margin to be respectively (a) > 1.7 and > 30º  (b) < 1.7 and > 30º (c) < 1.7 and < 30º (d) >1.7 and < 30º 10. The frequency at which maximum amplitude ratio is attained is called (a) corner frequency (b) resonant frequency  (c) cross-over frequency (d) natural frequency 11. A negative gain margin expressed in decibels means (a) a stable system (b) unstable system (c) critically damped system (d) both a and c 12. Bode diagram is a plot of (a) log (  AR  ) vs. log ( f  ) and Ø vs. log ( f  ) (b) log (  AR  ) vs. f   and log Ø vs. f   (c)  AR vs.log ( f  ) and Ø vs. log ( f  ) (d) log (AR) vs. log f 13. For measuring the temperature of a furnace, which is the most suitable instrument? (a) Platinum resistance thermometer (b) Thermocouple (c) Optical pyrometer (d) Bimetallic thermometer 14. Degree to which an instrument indicates the changes in measured variable without dynamic error is called (a) speed of response (b) reproducibility of instrument (c) fidelity (d) its static characteristics 15. Which of the following is a desirable characteristic of an instrument? (a) high drift (b) high fidelity (c) high temperature lag (d) poor reproducibility 16. Which of the following shows maximum dip affect (indicating reverse direction of temperature change)? (a) mercury thermometer (b) radiation pyrometer (c) bimetallic thermometer (d) thermocouple  Page 4 17. Pick out the most suitable instrument for measuring temperature in the range of -40 to 800ºF. (a) mercury thermometer (b) bimetallic thermometer  (c) radiation pyrometer (d) radiation pyrometer 18. Thermocouple is suitable for measuring (a) liquid temperatures only (b) very high temperatures only (c) very low temperatures only (d) both high and low temperatures 19. Which of the following relates the absorption and evolution of heat at the junctions of a thermocouple to the current flow in the circuit? (a) Seebeck effect (b) Peltier effect  (c) Joule heating effect (d) Thomson effect 20. Thermal wells are used in temperature measurement to (a) guard against corrosive and oxidizing action on thermocouple materials (b)   reduce measuring lag (c)   increase the fidelity (d)   increase the sensitivity 21. Gas analysis is commonly done using (a) thermal conductivity cell  (b) X-ray diffraction (c) mass spectrometer (d) emission spectrometer 22. Psychrometer determines (a) humidity of gases  (b) moisture content of solids (c) water of crystallization (d) hygroscopic nature of solids 23. Continuous measurement of moisture content of paper in paper industry is done by measuring (a)   thermal conductivity through the paper (b)   electrical resistance through the paper (c)   magnetic susceptibility (d)   both b and c 24. Optimal activity of a solution can be determined using a (a) polarimeter  (b) polarograph (c) dilatometer (d) refractometer
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks