Asymptotes

Q. Figure shows the root locus plot (location of poles not given) of a third order system whose open loop transfer function is

1. $\frac{K}{s^3}$
2. $\frac{K}{s^2(s+1)}$
3. $\frac{K}{s(s^2+1)}$
4. $\frac{K}{s(s^2-1)}$

Q. A unity feedback system has an open loop transfer function, $G\left(s\right)=\frac{K}{s^2}.$ Its root locus plot will be

1. 
2. 
3. 
4. 

Q. A unity feedback system has an open loop transfer function of the form

$KG\left(s\right)=\frac{K(s+a)}{s^2(s+b)};b>a$

Which of the loci shown in figure can be valid rootloci for the system?

1. 
2. 
3. 
4.