288. Amplidyne is a type of
A. Magnetic amplifier
B. Rotating amplifier
C. Electronic amplifier
D. Synchro transformer
289. A sampled signal has z-transform Tz R(z) ?2 ? Which of the following (z ? 1)time-domain signals does it represent?
A. Exponential
B. Step
C. Ramp
D. Sinusoidal
290. Consider the signals xi(t) = 2 sin nt + cos 4nt and x2(t) = sin 5nt + 3 sin 13 nt :
A. Both the signals are periodic
B. Both the signals are not periodic
C. xi is periodic, but x2 is not periodic
D. xi is not peiodic, but x2 is periodic
291. Given a unity feedback system with G(s) , the value of K for s(s + 4) damping ratio of 0.5 is
A.1
B.16
C.4
D.2
292. A unity feedback control system has forward path transfer function G(s) given by C(s)? , 10(1 + s) s`(s + 12) (s + 5) The steady-state error due to unit parabolic input r(t)= ?2 U(t) is t2
A. zero
B.0.5
C.1
D. infinite
293. For the control system with K(s + 2) G(s) H(s) s(s` + 2s + 3) the type number is
A.2
B.1
C.4
D.C 3
294. The root locus plot of a system having open loop transfer function K(s + 10) (s + 70) G(s) H(s) ? s' (s + 100) (s + 200) will have angle of asymptotes as
A. 60?, 1000
B. 60?, 180?, 300?
C. 60?, 120?, 180?
D. 60?, 90?, 120?
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