Process Control And Instrumentation Questions MCQs


process control and instrumentation Questions

Total Questions : 318

Page 1 of 16 pages
Question 1. An aneroid barometer measures the __________ pressure.
  1.    Atmospheric
  2.    Absolute
  3.    Vacuum
  4.    Gage
Answer: Option B
Question 2. Meleoid gauge measures the __________ pressure.
  1.    Positive
  2.    Sub-atmospheric
  3.    Very high
  4.    Atmospheric
Answer: Option B
Question 3. A manometer measures the __________ pressure.
  1.    Atmospheric
  2.    Absolute
  3.    Gauge
  4.    None of these
Answer: Option C
Question 4. Which of the following thermocouples is capable of measuring a temperature of -50°C?
  1.    Platinum - platinum + rhodium
  2.    Chromel - alumel
  3.    Iron-constantan
  4.    Copper - constantan
Answer: Option A
Question 5. Which of the following is not a variable area flow meter?
  1.    Piston type meter
  2.    Rotameter
  3.    Magnetic flow meter
  4.    Orifice and tapered plug meter
Answer: Option C
Question 6. Platinum resistance thermometer can be used upto antimony point which is __________ °C, and is the temperature of equilibrium between solid antimony & liquid antimony at normal atmospheric pressure.
  1.    961.93
  2.    630.74
  3.    1064.43
  4.    1261.93
Answer: Option B
Question 7. Thermal conductivity cell is the primary element of a/an __________ analyser.
  1.    Oxygen
  2.    Carbon dioxide
  3.    Carbon monoxide
  4.    Sulphur dioxide
Answer: Option B
Question 8. The transfer function of a process is 1/(16s² + 8s + 4). If a step change is introduced into the system, then the response will be
  1.    Under damped
  2.    Critically damped
  3.    Over damped
  4.    None of these
Answer: Option A
Question 9. Magnetic flowmeters are generally not used for the velocity/flow measurement of hydrocarbons due to their
  1.    Low thermal conductivity
  2.    Low electrical conductivity
  3.    High viscosity index
  4.    Low flash point
Answer: Option B
Question 10. Which of the following thermocouples has the least temperature measurement range?
  1.    Copper-constantan
  2.    Chromel-alumel
  3.    Platinum-platinum/rhodium
  4.    Iron-constantan
Answer: Option A
Question 11. Which thermocouple can be used to measure a temperature of around 1400°C ?
  1.    Copper-constantan
  2.    Aluminium-chromel
  3.    Platinum-platinum+rhodium
  4.    None of these
Answer: Option C
Question 12. The deflection of the free end of the bimetallic strips in a bimetallic thermometer with temperature is nearly
  1.    Linear
  2.    Non-linear
  3.    Parabolic
  4.    Hyperbolic
Answer: Option A
Question 13. Reset rate is the another term used for __________ time.
  1.    Dead
  2.    Integral
  3.    Derivative
  4.    None of these
Answer: Option B
Question 14. Pyrometry refers to the measurement of temperature
  1.    With the mercurial thermometer upto 350°C
  2.    Directly
  3.    Which is of higher magnitude
  4.    All of the above
Answer: Option C
Question 15. For measuring the temperature of a red hot furnace, which is the most suitable instrument?
  1.    Platinum resistance thermometer
  2.    Thermocouple
  3.    Optical pyrometer
  4.    Bimetallic thermometer
Answer: Option C
Question 16. Thermal wells are used in the temperature measurement to
  1.    Guard against corrosive and oxidising action on thermocouple materials
  2.    Reduce measuring lag
  3.    Increase the fidelity
  4.    Increase the sensitivity
Answer: Option A
Question 17. Thermocouple in a thermal well behaves as a true
  1.    First order system
  2.    Second order system (overdamped)
  3.    Multiple first order system
  4.    Second order system (underdamped)
Answer: Option C
Question 18. Thermistors are made of
  1.    Ultra pure metals
  2.    Metal oxides
  3.    Iron-copper alloys
  4.    Nickel-chromium alloys
Answer: Option B
Question 19. For increased speed of response of an expansion pressure spring thermometer, the thermometer bulb should have a
  1.    Large area but small mass
  2.    High thermal conductivity
  3.    Small specific heat
  4.    All of the above
Answer: Option D
Question 20. Suppose that the gain, time constant and dead time of a process with the following transfer function:Gc(s) = 10 exp( - 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as
  1.    8, 0.6, 0.08
  2.    12, 0.6, 0.12
  3.    8, 0.6, 0.12
  4.    12, 0.4, 0.08
Answer: Option B