Process Dynamics and Control Mid - I, September - 2014

1.For an under-damped 2nd order system as ς increases overshoot
  • Increases
  • decreases
  • no effect
  • cannot say
Answer: B
2.Addition of derivative action to PI action causes
  • Quick response
  • more oscillations
  • large offset
  • all the above
Answer: A
3.The settling time for the first order system is equal to __________of its time constant. To reach 95% of steady state output
  • Two
  • three
  • Four
  • Five
Answer: B
4.Pick the correct equation
  • Decay ratio= (Overshoot)2
  • Decay ratio =(Overshoot)1/2
  • Decay ratio= (Overshoot)3
  • none of the above
Answer: B
5.Which of the following has the highest maximum deviation
  • P
  • P-I
  • P-D
  • P-I-D
Answer: B
6.Laplace transform method is used for
  • Linear behavior
  • Non-linear behavior
  • neither A or B
  • Both A & B
Answer: A
7.A proportional controller with a gain of Kc is used to control a first order Process, the offset will increase if
  • Kc is increased
  • Kc is reduced
  • Integral control action is introduced
  • Derivative control action is introduced
Answer: D
8.Use of integral control along with proportional control facilitates
  • Reduction of offset
  • Reduction of stability time
  • Elimination of offset
  • None
Answer: C
9.Most commonly used controller for controlling the temperature is
  • P
  • PI
  • PD
  • PID
Answer: D
10.The offset of a PI controller is
  • I
  • 0
  • 2
  • 3
Answer: B
11.The reciprocal of the reset rate is ___________________
Answer: Integral time
12.___________________ controller has approximately zero band width.
Answer: PI
13.A feed back system implies _________________mechanism.
Answer: Servo
14.Two interacting first order systems when connected in series will approximate an__________second order system.
Answer: Over damped
15.Delay in the response of the controlled variable at a point of measurement to a change in the value of the manipulated variable is called ________________
Answer: Process lag
16.A device to compare the controlled variable with the desired value is called _____________
Answer: Comparator
17.The transfer function of transportation lag of τ time units is _________________
Answer: e-S
18.The steady state outputs of the transfer function s/(s+1)(s+2) for a unit slope ramp input is ________________
Answer: 42036
19.A system has a transfer function Y/X= 10/S2+6s+4). A step input of 4 units magnitude is introduced in this system. The % overshoot is________________
Answer: 25
20.A thermometer of time constant 10 seconds initially at 300 C is suddenly immersed into water at 1000c. the time taken for the thermometer reading to reach 900c is_________________
Answer: 19.5 sec