Process Control Multiple Choice Questions
Process Control Multiple Choice Questions
1. When we adjust integral time in a controller
a) We determine an RC time constant in the controller’s internal feedback path
b) We adjust the time it will take for integral to equal derivative
c) We set the process time constant so that it will always equal 1
d) What happens specifically depends on the type of controller, pneumatic
Answer: We determine an RC time constant in the controller’s internal feedback path
2. For proper feedback in a process control element, it is required to ________
a) measure P
b) measure set point
c) measure error
d) measure comparator
Answer: measure P
3. If in a proportional-plus-integral controller measurements away from the set point for a long period, the controller’s output will be
a) 0
b) Unknown
c) 0
d) 100 percent
Answer: 0
4. In the modem controller, derivative action is applied only to the
a) Error
b) Measurement
c) Setpoint
d) Integral circuit
Answer: Measurement
5. What is the main objective of process control?
a) to control physical parameters
b) to control mechanical parameters
c) to control optical parameters
d) to control electrical parameters
Answer: to control physical parameters
6. Gain and proportional bands are
a) Reciprocally related
b) Two different control modes
c) Adjusted independently 0f one another
d) Controller functions calibrated in time units
Answer: Reciprocally related
7. Physical parameters change due to ________
a) voltage
b) current
c) internal and external disturbances
d) power
Answer: internal and external disturbances
8. All control systems that fit into the usual pattern are
a) Open-Loop
b) Nonself-regulating
c) Closed-loop
d) On/off
Answer: Closed-loop
9. A process control system consists of ________
a) 10 elements
b) 6 elements
c) 2 elements
d) 4 elements
Answer: 4 elements
10. If it were possible for a proportional controller to have a true 0 percent proportional band, the controller gain would have to be
a) Unity
b) 0
c) 100
d) Infinite
Answer: Infinite
11. A transducer converts ________
a) mechanical quantity to electrical form
b) electrical quantity to physical form
c) physical quantity to electrical form
d) chemical quantity to physical form
Answer: physical quantity to electrical form
12. What is a process control system?
a) system to keep the parameters at zero value
b) system to maintain the parameters constant
c) system to keep the parameters at highest value
d) system to check the voltage
Answer: system to maintain the parameters constant
13. With a proportional-only controller, if measurement rules set point, the output will be
a) 0
b) 100 percent
c) 50 percent
d) Impossible to define
Answer: 50 percent
14. The function of the integral (reset) mode is to
a) Oppose change in measurement
b) Automatically adjust the controller’s gain
c) Eliminate offset
d) Stabilize the controlloop
Answer: Eliminate offset
15. A two-position controller (on/off) always
a) Controls with a fixed offset
b) Controls around a point
c) Automatically adjusts its integral time
d) Requires precise tuning
Answer: Controls around a point
16. A proportional controller will have an offset difference between set point and control point
a) At all times
b) Equal to the proportional band setting
c) That depends on process load
d) That will eventually vanish
Answer: That depends on process load
17. If the proportional band of the controller is adjusted to the minimum possible value, the control action is likely to be
a) On/off
b) With maximum otIset
c) Excellent
d) Inoperative
Answer: On/off
18. An electrical transducer consists of ________
a) 4 parts
b) 6 parts
c) 8 parts
d) 2 parts
Answer: 2 parts
19. If operating properly, automatic control will always
a) Reduce manpower
b) Reduce costs
c) Make the process operate more uniformly
d) Decrease maintenance
Answer: Make the process operate more uniformly
20. Automatic controllers operate on the difference between set point and measurement, which is called
a) Offset
b) Bias
c) Error
d) Feedback
Answer: Error
21. Select the correct statement from the following.
a) The amplitude ratio of a pure capacity process is inversely proportional to frequency.
b) The phase lag of a pure time delay system decreases with increasing frequency.
c) The amplitude ratio of a pure time delay system increases with frequency.
d) The frequency response of a pure capacity process is unbounded.
Answer: The amplitude ratio of a pure capacity process is inversely proportional to frequency.
22. Dilute wine was used as a thermometric liquid initially to develop temperature scale. First emperical temperature scale developed was the________scale.
a) Centigrade
b) Reaumer
c) Fahrenheit
d) Kelvin
Answer: Fahrenheit
23. A negative gain margin expressed in decibels means a/an _________ system.
a) unstable
b) critically damped
c) stable
d) none of these
Answer: unstable
24. A transducer is part of a large circuit and produces the required output.
a) True
b) False
Answer: True
25. Feedback path element measure only input parameters.
a) True
b) False
Answer: False
a) We determine an RC time constant in the controller’s internal feedback path
b) We adjust the time it will take for integral to equal derivative
c) We set the process time constant so that it will always equal 1
d) What happens specifically depends on the type of controller, pneumatic
Answer: We determine an RC time constant in the controller’s internal feedback path
2. For proper feedback in a process control element, it is required to ________
a) measure P
b) measure set point
c) measure error
d) measure comparator
Answer: measure P
3. If in a proportional-plus-integral controller measurements away from the set point for a long period, the controller’s output will be
a) 0
b) Unknown
c) 0
d) 100 percent
Answer: 0
4. In the modem controller, derivative action is applied only to the
a) Error
b) Measurement
c) Setpoint
d) Integral circuit
Answer: Measurement
5. What is the main objective of process control?
a) to control physical parameters
b) to control mechanical parameters
c) to control optical parameters
d) to control electrical parameters
Answer: to control physical parameters
6. Gain and proportional bands are
a) Reciprocally related
b) Two different control modes
c) Adjusted independently 0f one another
d) Controller functions calibrated in time units
Answer: Reciprocally related
7. Physical parameters change due to ________
a) voltage
b) current
c) internal and external disturbances
d) power
Answer: internal and external disturbances
8. All control systems that fit into the usual pattern are
a) Open-Loop
b) Nonself-regulating
c) Closed-loop
d) On/off
Answer: Closed-loop
9. A process control system consists of ________
a) 10 elements
b) 6 elements
c) 2 elements
d) 4 elements
Answer: 4 elements
10. If it were possible for a proportional controller to have a true 0 percent proportional band, the controller gain would have to be
a) Unity
b) 0
c) 100
d) Infinite
Answer: Infinite
11. A transducer converts ________
a) mechanical quantity to electrical form
b) electrical quantity to physical form
c) physical quantity to electrical form
d) chemical quantity to physical form
Answer: physical quantity to electrical form
12. What is a process control system?
a) system to keep the parameters at zero value
b) system to maintain the parameters constant
c) system to keep the parameters at highest value
d) system to check the voltage
Answer: system to maintain the parameters constant
13. With a proportional-only controller, if measurement rules set point, the output will be
a) 0
b) 100 percent
c) 50 percent
d) Impossible to define
Answer: 50 percent
14. The function of the integral (reset) mode is to
a) Oppose change in measurement
b) Automatically adjust the controller’s gain
c) Eliminate offset
d) Stabilize the controlloop
Answer: Eliminate offset
15. A two-position controller (on/off) always
a) Controls with a fixed offset
b) Controls around a point
c) Automatically adjusts its integral time
d) Requires precise tuning
Answer: Controls around a point
16. A proportional controller will have an offset difference between set point and control point
a) At all times
b) Equal to the proportional band setting
c) That depends on process load
d) That will eventually vanish
Answer: That depends on process load
17. If the proportional band of the controller is adjusted to the minimum possible value, the control action is likely to be
a) On/off
b) With maximum otIset
c) Excellent
d) Inoperative
Answer: On/off
18. An electrical transducer consists of ________
a) 4 parts
b) 6 parts
c) 8 parts
d) 2 parts
Answer: 2 parts
19. If operating properly, automatic control will always
a) Reduce manpower
b) Reduce costs
c) Make the process operate more uniformly
d) Decrease maintenance
Answer: Make the process operate more uniformly
20. Automatic controllers operate on the difference between set point and measurement, which is called
a) Offset
b) Bias
c) Error
d) Feedback
Answer: Error
21. Select the correct statement from the following.
a) The amplitude ratio of a pure capacity process is inversely proportional to frequency.
b) The phase lag of a pure time delay system decreases with increasing frequency.
c) The amplitude ratio of a pure time delay system increases with frequency.
d) The frequency response of a pure capacity process is unbounded.
Answer: The amplitude ratio of a pure capacity process is inversely proportional to frequency.
22. Dilute wine was used as a thermometric liquid initially to develop temperature scale. First emperical temperature scale developed was the________scale.
a) Centigrade
b) Reaumer
c) Fahrenheit
d) Kelvin
Answer: Fahrenheit
23. A negative gain margin expressed in decibels means a/an _________ system.
a) unstable
b) critically damped
c) stable
d) none of these
Answer: unstable
24. A transducer is part of a large circuit and produces the required output.
a) True
b) False
Answer: True
25. Feedback path element measure only input parameters.
a) True
b) False
Answer: False
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