logo

CuriousTab

CuriousTab

Discussion


Home Chemical Engineering Process Control and Instrumentation Comments

  • Question
  • Thermistor, which has high temperature co-efficient of resistivity, is used as the sensing element in resistance thermometer. It is a/an


  • Options
  • A. insulator
  • B. conductor
  • C. solid semi-conductor
  • D. liquid semi-conductor

  • Correct Answer
  • solid semi-conductor 


  • Process Control and Instrumentation problems


    Search Results


    • 1. Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference?

    • Options
    • A. Peltier effect
    • B. Thomson effect
    • C. Seebeck effect
    • D. none of these
    • Discuss
    • 2. Which of the following controllers has the least maximum deviation?

    • Options
    • A. P-controller
    • B. P-I controller
    • C. P-I-D controller
    • D. P-D controller
    • Discuss
    • 3. Which of the following thermocouples will give the highest output for the same value of hot and cold junction temperature?

    • Options
    • A. Platinum-platinum + rhodium.
    • B. Iron-constantan.
    • C. Chromel-constantan.
    • D. All will give the same output.
    • Discuss
    • 4. Which of the following is an undesirable dynamic characteristic of an instrument?

    • Options
    • A. Reproducibility
    • B. Dead zone
    • C. Time lag
    • D. Static error
    • Discuss
    • 5. Which of the following is not the triple point of water?

    • Options
    • A. 32°R
    • B. 273°K
    • C. 492°R
    • D. 32°F
    • Discuss
    • 6. Which of the following is a desirable characteristic of an instrument?

    • Options
    • A. High drift
    • B. High fidelity
    • C. High measuring lag
    • D. Poor reproducibility
    • Discuss
    • 7. Zirconia probe is used for the continuous measurment of __________ flue gases going out of the furnace.

    • Options
    • A. oxygen in
    • B. carbon dioxide in
    • C. carbon monoxide in
    • D. temperature of
    • Discuss
    • 8. Emf developed by a thermocouple, while measuring a temperature of 600°C is about 5.5 mV. The type of thermocouple used is

    • Options
    • A. chromel-alumel
    • B. iron-constantan
    • C. platinum-platinum+rhodium
    • D. either (a), (b) or (c)
    • Discuss
    • 9. Instrumentation in a plant offers the advantage of

    • Options
    • A. greater safety of operation
    • B. better quality of product
    • C. greater operation economy
    • D. all (a), (b) and (c)
    • Discuss
    • 10. A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if

    • Options
    • A. Kc is reduced.
    • B. Kc is increased.
    • C. integral control action is introduced.
    • D. derivative control action is introduced.
    • Discuss


    Comments

    There are no comments.

Enter a new Comment