Process Control System multiple choice questions

 Process Control System

1. 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
2. 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
3. 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
4. Physical parameters change due to ______
a) voltage
b) current
c) internal and external disturbances
d) power
Answer: internal and external disturbances
5. A process control system consists of _____
a) 10 elements
b) 6 elements
c) 2 elements
d) 4 elements
Answer: 4 elements
6. 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
7. Feedback path element measure only input parameters.
a) True
b) False
Answer: False
8. A transducer is part of a large circuit and produces the required output.
a) True
b) False
Answer: True
9. An electrical transducer consists of ______
a) 4 parts
b) 6 parts
c) 8 parts
d) 2 parts
Answer: 2 parts
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. 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
12. 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: a
13. 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
14. In the modem controller, derivative action is applied only to the
a) Error
b) Measurement
c) Setpoint
d) Integral circuit
Answer: Measurement
15. 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
16. 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
17. 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
18. 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
19. 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
20. 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
21. 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
22. Automatic controllers operate on the difference between set point and measurement, which is called
a) Offset
b) Bias
c) Error
d) Feedback
Answer: Error

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