CONTROL SYSTEM SET 21

 CONTROL SYSTEM SET 21

1. Bode analysis method can be applied
a) If transfer function has no poles and zeros on R.H. of s-plane
b) If transfer function has no poles on R.H. of s-plane
c) If transfer function has no zero on R.H. of s-plane
d) To all transfer functions
Ans: (a)
 
2. In a root locus plot, increase in 𝓴 will
a) Result in decrease in the damped and undamped natural frequencies
b) Result in increase in the damped and undamped natural frequencies
c) Not change the damped and undamped natural frequencies
d) None of these
Ans: (b)
 
3. Cut off is the slope of log-magnitude curve
a) At the start of curve
b) At the end of curve
c) Near the cut off frequency
d) None of these
Ans: (c)
 
4. Gain margin expressed in decibels is
a) Positive if Kg greater than 1 and negative for Kg less than 1
b) Negative if Kg greater than 1 and negative for Kg less than 1
c) Always zero
d) Infinity for Kg equal to 1
Ans: (a)
 
5. Bandwidth gives an indication of
a) Characteristic equation of the system
b) Speed of response of a control system
c) Transfer function of the control system
d) Transients in the system
Ans: (b)
 
6. Nyquist stability criterion requires polar plot of
a) Characteristic equation
b) Closed loop transfer function
c) Open loop transfer function
d) None of these
Ans: (c)
 
7. Cut off frequency is the frequency at which magnitude of closed loop frequency response is
a) 1 db below its zero frequency
b) 2 db below its zero frequency
c) 3 db below its zero frequency
d) 4 db below its zero frequency
Ans: (c)
 
8. In Nyquist criterion roots of the characteristic equation are given by
a) Zeros of open loop transfer function
b) Zeros of closed loop transfer function
c) Poles of closed loop transfer function
d) Poles of open loop transfer function
Ans: (c)
 
9. For all frequencies, a unit circle in the Nyquist plot transformer into
a) Db line of amplitude plot in Bode diagram
b) 1 db line of amplitude plot in Bode diagram
c) Either (a) and (b)
d) None of these
Ans: (c)
 
10. Transfer founction, when the bode diagram is plotted should be of the form
a) (1+T)
b) (1+S)
c) (Ts)
d) (1+Ts)
Ans: (d)