Que Bank-A PDF

MCQs for minor subject: Process control loop components Question1 The variable which is adjusted manually or by means of control mechanism is called_______. A controlled variable B set point value C manipulated variable D l...

MCQs for minor subject: Process control loop components Question1 The variable which is adjusted manually or by means of control mechanism is called_______. A controlled variable B set point value C manipulated variable D load variable Question2 Identify this symbol. A Pneumatic signal line B Electric signal line C Hydraulic signal line D Fiber optic signal line Question3 In flow control loop, the range of the flow rate is given as 0 LPH to 100 LPH. The 75 LPH flow rate corresponds ________ of current. A 16 mA B 7.5 mA C 10mA D 0.75mA Question4 In 4-20 mA current signal, 4 mA current represents_____________ value. A 1% B 0.4% C 4% D 0% Question5 The basic function of electronic transmitter is to A respond to measurand and convert it into 4-20mA signal B respond to process variable and convert it into 4-20mA signal C respond to controlled variable and convert it into 4-20mA signal D All above Question6 Which of the following accessory can be used in installation of DPT for flow rate measurement. A Impulse line B Manifold valve C Orifice plate D All above Question7 In level measurement, zero elevation is necessary, when________________ A pressure on both sides of transmitter are equal. B pressure on low pressure side of transmitter is low at atmospheric pressure. C pressure on high pressure side of transmitter is high than low pressure side of transmitter D pressure on low pressure side of transmitter is high than high pressure side of transmitter Question8 Manifold is __________ A pressure measurement sensor in DPT B type of control valve C transmitter D solenoid valve Question9 In liquid pressure control loop, _______________ control action is recommended. A proportional-integral B proportional-derivative C integral-derivative D only derivative Question10 In on-off control mode, to avoid cycling behaviour of controller_________ is purposely provided. A dead time B neutral zone C bang-bang gap D lag time Question11 Suppose, a process error lies within the neutral zone with P= 25%. At t=0, the error falls below the neutral zone. If K= 2% per second, find the time when the output saturates. A T= 3.76 sec. B T= 37.6 min. C T= 0.376 sec. D T= 37.5 sec. Question12 If the critical gain is 26, what is the proportional gain of single mode controller? A 14.3 B 2.6 C 11.7 D 13 Question13 In quarter amplitude decay ratio, the magnitude of first overshoot is 16. What is the magnitude of second overshoot. A 8 B 4 C 2 D 0 Question14 Setting of optimum values of proportional gain, integral time and derivative gain in PID controller to improve its performance is called _______________ of controller. A calibration B resetting C tuning D biasing Question15 The 9% change in controlling variable causes 3.9% change in controlled variable in 4.8 minute. Determine the process reaction rate. A 0.8 %/min. B 1.87 %/min. C 1.06 %/min. D 0.731 %/min Question16 Identify the experimental step to implement the Z-N open loop method of controller tuning. A Keep integral time and derivative time to its zero value. B Increase the proportional gain gradually up to critical gain C Determine critical period of oscillations. D Disconnect the controller output from final control element. Question17 In power plant, pressure control loop no. 071 uses current to pressure converter as one of the component, the actuator used in this loop is___________. A Electrical type B Hydraulic type C Pneumatic type D Handwheel type Question18 Which of the following characteristic gives good control and high rangeability. A Equal percentage characteristics B Quick opening characteristics C Linear characteristics D All above characteristics Question19 Identify which of the following is the part of trim in control valve.  A Closure member B Bonnet C Diaphragm D Spring Question20 Which of the valve is rotary type of control valve. A Globe valve B Butterfly valve C Needle valve D Y angle valve Question21 U.S. no. of gallons of water that passes through fully open valve in one minute with pressure drop of 1 psi across it at 60° F is called_________. A control valve coefficient B control valve size C raynolds number D port size of valve Question22 Which of the following component improve the performance of control valve. A Trim B Actuator C Positioner D Closure member Question23 Which of the following is pressure reducing device. A Differential pressure transmitter B Current to pressure converter C Pressure to current converter D Control valve