CONTROL SYSTEM MCQS SET 36

CONTROL SYSTEM MCQS SET 36

1. The range of K for the stability of system is 0<K<100. For K =10, The gain Margin of the system
a) 10         b) 5           c) 0.1             d) 0.5
Answer: a

2. The frequency at which the Nyquist diagram cuts the unit circle is known as:
a) Gain crossover frequency
b) Phase crossover frequency
c) Damping frequency
d) Corner frequency
Answer: a

3. The forward path transfer function of a unity feedback system is given by G(s) = 1/(1+s)^2. What is the phase margin of the system?
a) –π rad          b) 0 rad           c) π/2 rad          d) π rad
Answer: d

4. Consider the following statements:
1. The delay time is the time required to reach 50% of the final value in the first time.
2. The rise time is the time required for the response to rise from 10% to 90% of its final value for underdamped systems.
3. The rise time is the time required for the response to rise from 0 to 100% for the underdamped systems.
Which of these statements are correct?
a) 1,2 and 3 only                     b) 1 and 2 only
c) 1 and 3 only                         d) 2 and 3 only negative real axis
Answer: c

5. For minimum phase systems:
a) Pole must lie on left plane             b) Zeroes must lie on left plane
c) Poles and zeroes must lie on left plane
d) Both must lie on right plane
Answer: c

6. For non-minimum phase systems:
a) Poles and zeroes must lie on the right s-plane
b) Zeroes must lie on right of s-plane
c) Both lie on left of s-plane
d) Poles must be on the left and zeroes can be on the right s –plane.
Answer: d

7. For all-pass systems:
a) Poles must lie on right of the s-plane
b) Zeroes must lie on the left of s-plane
c) Poles must lie on the left and zeroes on the mirror image of the pole can be on the right
d) None of the mentioned
Answer: c

8. All pass system and minimum phase system constitute_________________
a) Pole must lie on left plane
b) Minimum phase system
c) Non-minimum phase system
d) Both must lie on right plane
Answer: c

9. Minimum phase systems have unique relationship between its phase and magnitude curves
a) True             b) False
Answer: a

10. The impulse response of a LTI system is a unit step function, then the corresponding transfer function is
a) 1/s             b) 1/s2                  c) 1                  d) s
Answer: a