-
The open-loop transfer function of a feedback control system is given by
G(s) H(s) = K(s + 2) s(s + 4)(s2 + 4s + 8)
I n the r oot locus diagram of the system, the asymptotes of the root loci for large values of K meet a point in the s-plane. Which one of the following is the set of co-ordinate of that point?
-
- (– 1, 0)
- (– 2, 0)
-
-10 , 0 
3 - (2, 0)
Correct Option: B
Given open-loop transfer function has one zero at s = – 2 and four poles at s = 0, – 4, – 2 + s and – 2– s respectively.
The point at which asymptates meet is called centroid and is given by
| σA = | ||
| number of poles - number of zero |
| = | ||
| 4 - 1 |
| = | = -2 | |
| 3 |
Hence co-ordinates are (– 2, 0)
