CONTROL SYSTEM MCQs SET 27

CONTROL SYSTEM MCQs SET 27

1. Consider the following statements regarding root loci:
a) All root loci start from the respective poles of G(s) H(s)
b) All root loci end at the respective zeros of G(s) H(s) or go to infinity
c) The root loci are symmetrical about the imaginary axis of the s-plane
d) All root loci start and end from the respective poles of G(s) H(s) or go to infinity
 

Answer: b

2. Number of roots of characteristic equation is equal to the number of ______________
a) Branches
b) Root
c) Stem
d) Poles
 

Answer: a
3. Which of the following statements are correct?
a) Root locus is for the negative feedback systems
b) Complementary root locus is for the positive feedback systems
c) Root locus is for the negative feedback and Complementary root locus is for the positive feedback systems
d) Complementary root locus is for the negative feedback systems
 

Answer: c

4. Consider the loop transfer function K(s+6)/(s+3)(s+5) In the root locus diagram the centroid will be located at:
a) -4
b) -1
c) -2
d) -3
 

Answer: c

5. Which one of the following applications software’s is used to obtain an accurate root locus for?
a) LISP
b) MATLAB
c) dBase
d) Oracle
 

Answer: b
6. Which one of the following is not the property of root loci?
a) The root locus is symmetrical about imaginary axis
b) They start from the open loop poles and terminate at the open loop zeroes
c) The breakaway points are determined from dK/ds = 0
d) Segments of the real axis are the part of the root locus if and only is the total number of real poles and zeroes to their right is odd.
 

Answer: a
7. The breakaway point calculated mathematically must always lie on the root locus.
a) True
b) False
 

Answer: a

8. What is the number of the root locus segments which do not terminate on zeroes?
a) The number of poles
b) The number of zeroes
c) The difference between the number of poles and zeroes
d) The sum of the number of poles and the number of the zeroes
 

Answer: c

9. Which one of the following are correct?
The root locus is the path of the roots of the characteristic equation traced out in the s-plane?
a) As the input of the system is changed
b) As the output of the system is changed
c) As a system parameter is changed
d) As the sensitivity is changed
 

Answer: c

10. If the gain of the system is reduced to a zero value, the roots of the system in the s-plane,
a) Coincide with zero
b) Move away from zero
c) Move away from poles
d) Coincide with the poles
 

Answer: d