Root Locus MCQ

21. Acontrol system has

$G(s)H(S)=\frac{K}{s(s + 4) (s^2 + 4s + 20)}$

(0 < K < ∞)

What is the number of breakaway points in the root locus diagram?

1. One
2. Two
3. Three
4. Zero

22. The loop transfer function of a system is given by

$G(s)H(s)=\frac{K(s+10)^{2}(s+100)}{s(s+25)}$

The number of loci terminating at infinity is

1. 0
2. 1
3. 2
4. 3

23. Which of the following are the characteristics of the root locus of

$G(s)H(s)=\frac{K(s+5)}{(s+1)(s+3)}$

1. It has one asymptote.
2. It hs intersection with jω-axis.
3. It has two real axis intersections.
4. It has two zeros at infinity.

1. i only
2. ii and iii only
3. iii and iv only
4. i and iii only

24. The characteristic equation of a feedback control system is given by s³ + 5s² + (K+6)s + K = 0. In the root loci diagram, the asymptotes of the root loci diagram, the asymptotes of the root loci for large ‘K’ meet at a point in the s-plane whose coordinates are

1. (2, 0)
2. (-1,0)
3. (-2,0)
4. (-3,0)