Process Control Multiple Choice Questions

 Process Control Multiple Choice Questions

1. Which of the following parameters is not useful in the construction of pressure bellows?
a) Hysteresis
b) Sensitive to changing pressures
c) Corrosion
d) pH
Answer: pH
2. Who invented the Bourdon tube?
a) Eugene
b) Howe
c) Flynn
d) Royce
Answer: Eugene
3. Which of the following is a desirable characteristic of an instrument ?
a) High fidelity
b) High drift
c) Poor reproducibility
d) High measuring lag
Answer: High fidelity
4. Thermistor, which has high temperature co-efficient of resistivity, is used as the sensing element in resistance thermometer. It is a/an
a) insulator
b) conductor
c) solid semi-conductor
d) liquid semi-conductor
Answer: solid semi-conductor
5. Which of the following temperature measuring instruments need not touch the object whose temperature is being measured ?
a) Thermo electric pyrometer
b) Mercury in glass thermometer
c) Filled system thermometer
d) Radiation/infrared pyrometer
Answer: Radiation/infrared pyrometer
6. Dilute wine was used as a thermometric liquid initially to develop temperature scale. First emperical temperature scale developed was the __________ scale.
a) Kelvin
b) Farenhite
c) Reaumer
d) Centigrade
Answer: Farenhite
7. Flapper nozzle is used in a/an __________ controller.
a) electronic
b) hydraulic
c) pneumatic
d) none of these
Answer: pneumatic
8. Smoke density of the flue gas going out of the chimney is measured by a
a) polarograph
b) thermal conductivity meter
c) photo electric cell
d) chromatograph
Answer: photo electric cell
9. Response of a system to a sinusoidal input is called __________ response.
a) impluse
b) frequency
c) unit step
d) none of these
Answer: frequency
10. The operation of a rotameter is based on
a) variable flow area.
b) pressure at a stagnation point.
c) rotation of a turbine.
d) pressure drop across a nozzle.
Answer: variable flow area.
11. Load cells are used for the measurement of
a) stress
b) velocity
c) strain
d) weight
Answer: weight
12. The closed loop pole of a stable second order system could be
a) complex conjugate with positive real parts.
b) both real and negative.
c) both real and positive.
d) one real positive and the other real negative.
Answer: both real and positive.
13. 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.
Answer: Mercury in glass thermometer kept in boiling water.
14. Working principle of radiation pyrometer is based on the
a) Seebeck effect
b) Stafan-Boltzman law
c) Wien's law
d) Kirchoffs law
Answer: Stafan-Boltzman law
15. A negative gain margin expressed in decibels means a/an __________ system.
a) unstable
b) stable
c) critically damped
d) none of these
Answer: unstable
16. Which of the following is an undesirable dynamic characteristic of an instrument ?
a) Reproducibility
b) Dead zone
c) Time lag
d) Static error
Answer: Time lag
17. Which of the following is the dynamic characteristics of an instrument ?
a) Fidelity
b) Dead zone
c) Sensitivity
d) Reproducibility
Answer: Fidelity
18. Which of the following devices is not used for pressure measurement?
a) Diaphragm gauge
b) Pressure bellows
c) Strain gauge
d) Dynamometer
Answer: Dynamometer
19. Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference ?
a) Peltier effect
b) Thomson effect
c) Seebeck effect
d) none of these
Answer: Thomson effect
20. The __________ of a vapor pressure thermometer is a functioning element.
a) pointer
b) bourdon tube
c) bulb
d) none of these
Answer: pointer
21. Which of the following measures the pressure with change in electrical resistance?
a) Bourdon tube
b) Pressure bellows
c) Strain gauge
d) Diaphragm gauge
Answer: Strain gauge
22. The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an __________ thermocouple.
a) chromel-alumel
b) platinum-platinum/rhodium
c) iron-constantan
d) none of these
Answer: iron-constantan
23. Which of the following is not the triple point of water ?
a) 32°F
b) 273°K
c) 492°R
d) 32°R
Answer: 32°R
24. Typical specifications for design stipulates the gain margin and phase margin to be respectively
a) > 1.7 and < 30°
b) < 1.7 and < 30°
c) < 1.7 and > 30°
d) > 1.7 and > 30°
Answer: > 1.7 and > 30°
25. Smoke density of the flue gas going out of the chimney is measured by a photo electric cell
a) True
b) False
Answer: True


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