CONTROL SYSTEM MCQS SET 35

CONTROL SYSTEM MCQS SET 35

1. All the constant N-circles in G planes cross the real axis at the fixed points. Which are these points?
a) -1 and origin        b) Origin and +1         c) -0.5 and 0.5      d) -1 and +1
Answer: a

2. Consider the following statements:
Nichol’s chart gives information about.
i. Closed loop frequency response.
ii. The value of the peak magnitude of the closed loop frequency response Mp.
iii. The frequency at which Mp occurs.
Which of the above statements are correct?
a) 2 and 3          b) 1 and 2            c) 1 and 3          d) 1,2 and 3
Answer: d

3. Which one of the following statements is correct? Nichol’s chart is useful for the detailed study analysis of:
a) Closed loop frequency response
b) Open loop frequency response
c) Close loop and open loop frequency responses
d) None of the above
Answer: a

4. In a bode magnitude plot, which one of the following slopes would be exhibited at high frequencies by a 4th order all-pole system?
a) -80dB/decade          b) -40 dB/decade         c) 40 dB/decade
d) 80 dB/decade
Answer: a

5. Frequency range of bode magnitude and phases are decided by :
a) The lowest and higher important frequencies of dominant factors of the OLTF
b) The lowest and highest important frequencies of all the factors of the open loop transfer function
c) Resonant frequencies of the second factors
d) None of the above
Answer: d

6. OLTF contains one zero in right half of s-plane then
a) Open loop system is unstable
b) Close loop system is unstable
c) Close loop system is unstable for higher gain
d) Close loop system is stable
Answer: c

7. The critical value of gain for a system is 40 and gain margin is 6dB. The system is operating at a gain of:
a) 20            b) 40           c) 80        d) 120
Answer: a
8. Nichol’s chart is useful for the detailed study and analysis of:
a) Closed loop frequency response
b) Open loop frequency response
c) Close loop and open loop frequency responses
d) open loop and Close loop frequency responses
Answer: a

9. The roots of the characteristic equation of the second order system in which real and imaginary part represents the :
a) Damped frequency and damping
b) Damping and damped frequency
c) Natural frequency and damping ratio
d) Damping ratio and natural frequency
Answer: b

10. A minimum phase unity feedback system has a bode plot with a constant slope of -20dB/decade for all frequencies. What is the value of the maximum phase margins of the system?
a) 0°             b) 90°         c) -90°           d) 180°
Answer: b