8. A synchro-transmitter receiver unit is a

A. two-phase ac device

B. 3-phase ac device

C. dc device

D. single-phase ac device

9. Which one of the following is an example of open-loop system?

A. A windscreen wiper

B. Aqualung

C. Respiratory system of an animal

D. A system for controlling anti-rocket missiles.

10. The correct sequence of steps needed to improve system stability is

A. insert derivative action, use negative feedback reduce gain

B. reduce gain, use negative feedback, insert derivation action

C. reduce gain, insert derivation action, use negative feedback

D. use negative feedback, reduce gain, insert derivation action.

11. Consider the system x(t) = [o i] X(t) + [b2] u(t) 1 1bi c(t) = d1d2 X (t) The conditions for complete state controllability and complete observability is

A. di >0, b2 >0, bi and d2 can be anything

B. di > 0, d2 > 0, bi and b2 can be anything

C. bi >0, b2 > 0, di and d2 can be anything

D. bi > 0, b2 > 0, bi and di can be anything

12. Canonical decomposition of a linear time invariant system is given by

A. completely controllable and observable

B. completely controllable and unobservable

C. uncontrollable but observable

D. neither completely controllable not observable

13. The transfer function of a system is given by 1 G (jo)) = (jo)) (juiT + 1) , K < ?T Which one of the following is the Bode plot of this function?

A. 0 log K0.1/T

B. 10fT cg,.?40 dB/decade

C.-20 dB/decade

D. -20dB/decade(0=K0.1/T

14. The main drawback of a feedback system is

A. inaccuracy

B. inefficiency

C. insensitivity

D. instability

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