Question

14. Which of the following define a BIBO (Bounded input bounded output) system? One or more answers could be correct. S H(s) (s-5) (s+10) 1 H(s) = (s+5) s(s+10) H(s) (s+5) (s+100)(s+10) H(S) = $2+100 H(s) = s3

Answer 1

1) BIBO stable. Since pole S= -10 on left half of S-plane.

30 July 5:54 406 characters Y(s)=T(s)*R(s)= N(s)/D(s), where T(s) is closed loop transfer function and R(s) is input to the system. For y(t) to be bounded, all the roots of D(s) should lie in left half of the s plane. It can have roots on imaginary axis (but not multiple root on same point). According to BIBO output it should be bounded for every bounded input. So poles of system transfer function should lie in the left half of the s plane(excluding imaginary axis as bounded input can have poles on imaginary axis).

2) BIBO stable. One pole at origin S=0 and another pole at S=-10.

3) BIBO stable . Both the poles S=-100 and S=-10 on left half of S-plane.

4) Not BIBO stable.

Since s^2= -100 I.e multiple roots on imaginary axis.

5)Not BIBO stable.

Since multiple poles at origin.