295. Consider the equations : 2s4+s3+3s2+ 5s+ 10=0 The number of roots this equation has in the right-half of s-plane is

A. one

B. two

C. three

D. four

296. The Nyquist plot of a system passes through (-1, j0) point in the CH plane. The phase margin of the system is

A. > 0

B. zero

C. < 0

D. infinite

297. For a fixed choice of steady-state velocity-error, the use of derivative output compensation in a proportional second order control system increases which of the following? I. Settling time 2. Undamped natural frequency 3. Damping ratio Select the correct answer using the codes given below :Codes :

A. I , 2 and 3

B. 1 and 2

C. 2 and 3

D. 1 and 3

298. The open loop transfer function of a unity feedback system is given as G(S) ?s + 1The bandwidth for this system, under open loop and closed loop operations are respectively :

A. 0.5 and 1.0 rad/s

B. 1.0 and 0.5 rad/s

C. 1.0 and 2.0 rad/s

D. 2.0 and 1.0 rad/s

299. Consider the following statements for a single - phase hysteresis motor : 1. Torque is constant from standstill up to synchronous speed Ns.2. Rotor is provided with narrow slots embedded with bars.3. Torque at starting is somewhat more than that at synchronous speed Ns.4. As the name suggests, only hysteresis torque is produced from zero speed right up to Ns.5. Rotor material possesses very wide hysteresis loop.Which of tilt statements given above are correct?

A. 1, 2 and 5

B. 3 and 5

C. I and 4

D. 2, 3 and 4

300. consider a system having forward path and feedback path transfer functions as 16/1s(s + 0.8)] and (1 + 2s) respectively. Which is the characteristic polynomial of the system?

A. s2 + 0.8s + 16

B. s2 + 2.8s + 16

C. s2 + 32.8s + 16

D. s2 + 32s + 16

301. Which of the following are correct? The feedback affects the control system in the following ways : 1. Increases accuracy but reduces sensitivity of gain to variation in system parameters. 2. Increases bandwidth and reduces the effect of non-linearity.3. Increases tendency towards oscillation or leads even to instability.Select the correct answer using the code given below :Codes :

A. 1 and 2

B. 1 and 3

C. 2 and 3

D. 1, 2 and 3

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