This set of Process Control Multiple Choice Questions & Answers (MCQs) focuses on “Uses of Industrial Controllers”.
1. What type of controller is used for the control of temperature of CSTR carrying out exothermic reaction with coolant flow in the jacket?
a) P controller
b) PD controller
c) PID controller
d) PI controller
View Answer
Explanation: The reaction temperature in a reactor is critical parameter. Hence high precision is required for the same. PID controller offer the highest precision. Hence PID controller needs to be used.
2. What type of controller is used for the control of pressure of distillation column by manipulating the vapour flow rate escaping from the top plate?
a) PD controller
b) PID controller
c) P controller
d) PI controller
View Answer
Explanation: The pressure of distillation column is a critical parameter. Hence high precision is required for the same. PID controller offer the highest precision. Hence PID controller needs to be used.
3. What type of controller is used for the control of flow of liquid from a pump?
a) P controller
b) PD controller
c) PID controller
d) PI controller
View Answer
Explanation: The flow is not a critical parameter. Hence high precision is not required for the same. Hence PI controller can be used which offer better precision than P controller.
4. Which of the following is correct for a control valve characteristic?
a) The product of the process gain and control valve is linear increasing function of the manipulated variable
b) The product of the process gain and control valve is linear decreasing function of the manipulated variable
c) The product of the process gain and control valve is exponentially decreasing function of the manipulated variable
d) The product of the process gain and control valve is exponentially increasing function of the manipulated variable
View Answer
Explanation: A control valve is selected in such a way that the product of the process gain and control valve is exponentially increasing function of the manipulated variable. It should not be linearly increasing or decreasing.
5. Which of the following options is correct for a p-controller?
a) Offset will increase if the value of controller gain decrease
b) Offset will decrease if the value of controller gain decrease
c) Offset will increase if the value of controller gain increase
d) Offset is independent of controller gain
View Answer
Explanation: For a p-controller the offset is inversely proportional to the controller gain. That means, higher the gain, lower will be the offset, which is favorable.
6. Which of the following options is correct for a p-controller?
a) Proportional band is inversely proportional to the controller gain
b) Proportional band is directly proportional to the controller gain
c) Proportional band is independent of the controller gain
d) Proportional band is equal to the product of controller gain and process gain
View Answer
Explanation: Proportional band is represented by –
PB = \(\frac {100}{controller gain}\)
So, the proportional band is inversely proportional to the controller gain.
7. Which of the following statement is correct?
a) Offset will increase if the value of controller gain decrease
b) Offset will decrease if the value of controller gain decrease
c) Offset will increase if the value of controller gain increase
d) Offset is independent of controller gain
View Answer
Explanation: For a p-controller the offset is inversely proportional to the controller gain. That means, higher the gain, lower will be the offset, which is favorable.
Sanfoundry Global Education & Learning Series – Process Control.
To practice all areas of Process Control, here is complete set of Multiple Choice Questions and Answers.