64. In the root-locus for open-loop transfer function K(s + 6) G(s) H(s) = (s + 3) (s + 5) the 'break away' and 'break-in', points are located respectively at
65. If the open-loop transfer function of the system is G(s) H(s) ?s(s + 8) (s + 16) (s + 72) then a closed loop pole will be located at s = ?12, when the value of K is
66. An electromechanical device which accurates a train of step angular movements is response to a train of input pulses on one to one basis is
68. Which one of the following transducers is used to obtain the output position in a position control system?
69. Consider the following statements regarding the number of sign changes in the first column of the Routh table in respect of the characteristic equation s2 + 2as + 4. TE a = + E, where E = near zero, the number of sign changes will be equal to zero. 2. If-a = 0, the number of sign changes will be equal to I. 3. If a = 1 E, where E = near zero, the number of sign changes will be equal to 2 Of these statements
70. Consider the following expressions which indicate the step or impulse response of an intially relaxed control system : 1. (5 ? 4e-2t) u (t) 2. (e-2t + 5) u (t) 3. 8(t) + 8e-2t u (t) 4. 8(t) + 4e-2t u(t) Those which correspond to the step and impulse response of the same system include
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