323.  A Hilbert transformer is a
A. non-linear system
B. non-causal system
C. time-varying system
D. low-pass system

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324.  The transfer function of a plant is T(s) 5 . The second-order (s+5)(s2 +s+1) approximation of T(s) using dominant pole concept is `(a) (s+ 5)(s + I)
A. (s +5)(s + I)
B.(c) S2+s+1
C. s2-1-S-4-1
D.

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325.  The open-loop transfer function of a plant is given as G(s)= s2. If the plant is operated in a unity feedback configuration, then the lead compensator that can stabilize this control system is10(s-1)10(s+4)
A. s+10
B.s+2
C.10(s+ 2)
D.1(s+2)

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326.  A unity feedback control system has an open-loop transfer function
A.5
B.5.5
C.1
D.10

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327. G(s) ?(s + 1) (s ? 7)For K> 6, the stability characteristic of the open-loop and closed-loop configuration of the system are respectively
A. stable and stable
B. unstable and stable
C. stable and unstable
D. unstable and unstable

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