148. Which of the following system provi des provides excellent transient as well as steady state response?
A. proportional action
B. proportional plus integral action
C. proportional plus differential action
D. proportional plus integral actions plus differential action

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149. In an absolutely stable control system, oscillations
A. can not set up at all
B. can be set up but may be controlled
C. set up automatically get damped out eventually
D. are always present

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150.  Main cause of absolute instability in a
A. parameters of controlling system
B. parameters of the controlled system
C. parameters of the feedback system
D. error detector where the two signals are compared

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151.  The output of the controller in control system is fed to
A. amplifier
B. comparator
C. final control element
D. sensor

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152.  The on-off controller is a
A. linear device
B. nonlinear device
C. discontinuous device
D. none of these

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153.  The input to a controller is
A. a servo signal
B. an error signal
C. a sensed signal
D. none of these

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154.  Error signal in a control system is
A. the difference between the measured value and the set value
B. the sum of the measured value and the set value
C. the ratio of the measured value to the set value
D. the ratio of the set value to the measured value

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