-
The root locus plot is shown below. What is the transfer function?
-
-
4 1 + s
-
4 (s + 1)2
-
4 (s + 1)3
-
4 (s + 1)4
-
Correct Option: D
From root locus plot it is clear that there are 4 asymptotes with angles 45°, 135°, 225° and 315°. and from equation
| ± | ×180° | |
| p – z | ||
where K = 0, 1, 2, 3. suggest 4 poles and no zeros.
| Centroid; σ = | |
| p – z |
| = | = - 1 | |
| 4 |
So
| T.F. = | (as K = 4 is given) | |
| (s + 1)4 |
