Discussion
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- Question
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
- Correct Answer
- High fidelity
- 1. 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 Discuss
- 2. 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
- 3. 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
- 4. 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
- 5. 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
- 6. 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
- 7. 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
- 8. 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
- 9. 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
- 10. A negative gain margin expressed in decibels means a/an __________ system.
Options- A. stable
- B. unstable
- C. critically damped
- D. none of these Discuss
Process Control and Instrumentation problems
Search Results
Correct Answer: solid semi-conductor
Correct Answer: Thomson effect
Correct Answer: P-D controller
Correct Answer: Chromel-constantan.
Correct Answer: Time lag
Correct Answer: oxygen in
Correct Answer: platinum-platinum+rhodium
Correct Answer: all (a), (b) and (c)
Correct Answer: Kc is increased.
Correct Answer: unstable
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