On-off control which is a special case of proportional control, has a band width of about _____________ percent?

Related Mcqs:

1. Find the ultimate gain and frequency for a proportional controller in the case of a process having the transfer function Gp(s) = 1/(4s + 1)(2s + 1)(s + 1) ?

   A. w = 1/√14, Kc = 45/7 √14
   B. w = √(7/6), Kc = 46/3
   C. w = 1, Kc = 13
   D. w = √(7/8), Kc = 45/4

2. Stabilising time for the controllers is the time required for the response to reach _____________ percent of its ultimate value?

   A. 63.2
   B. 87.5
   C. 95
   D. 100

3. The transfer function for an ideal proportional plus reset controller (reset time T) is_______________?

   A. Kc[1 + (1/TS)]
   B. Kc(1 + TS)
   C. Kc/(1 + TS)
   D. Kc/[1 + (s/T)]

4. A photo electric device in which the resistance of the metal is directly proportional to the light striking on it, is known as photo-conductive cell. Photoelectric transducers are used for the measurement of those parameters, which can be used to produce variation in_______________?

   A. Light intensity
   B. Current
   C. Flux density
   D. Voltage

5. The offset introduced by proportional controller with gain Kc in response of first order system can be reduced by ____________________?

   A. Reducing value of Kc
   B. Introducing integral control
   C. Introducing derivative control
   D. None of the above

6. The deflection in diaphragm (which is used as pressure sensor in pneumatic and electronic instruments) is dependent on the metal thickness, its diameter D. and shape & number of corrugations. Its deflection is proportional to_______________?

   A. d
   B. d2
   C. d3
   D. d4

7. Suppose that the gain, time constant and dead time of a process with the following transfer function: Gc(s) = 10 exp( – 0.1s)/(0.5s + 1) are known with a possible error of ± 20% of their values. The largest permissible gain Kc of a proportional controller needs to be calculated below taking the values of process gain, time constant and dead time as________________?

   A. 8, 0.6, 0.08
   B. 12, 0.6, 0.12
   C. 8, 0.6, 0.12
   D. 12, 0.4, 0.08

8. A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if________________?

   A. Kc is reduced
   B. Kc is increased
   C. Integral control action is introduced
   D. Derivative control action is introduced

9. A barometer measures the _____________ pressure?

   A. Absolute
   B. Gauge
   C. Absolute as well as gauge
   D. dynamic

10. The temperature of tempering oil baths maintained at 400°C during heat treatment of steel is measured by a/an _____________ thermocouple?

    A. Chromel-alumel
    B. Iron-constantan
    C. Platinum-platinum/rhodium
    D. None of these