Test: Frequency Response

Answer: a
Explanation: Asymptotic plots are the bode plots that are drawn to find the relative stability of the system by finding the phase and gain margin and this was invented by Scientist Bode.

Answer: c
Explanation: Root locus technique is used to find the transient and steady state response characteristics by finding the locus of the gain of the system and this was made Scientist Evans .

Answer: b
Explanation: Nyquist plot is used to find the stability of the system by open loop poles and zeroes and the encirclements of the poles and zeroes and satisfying the equation N=P-Z and this is named under the name of scientist Nyquist.

Answer: d
Explanation: Phase crossover frequency is the frequency at which the gain of the system must be 1 and for a stable system the gain is decibels must be 0 db.

Answer: d
Explanation: Closed loop system resonance frequency is the frequency at which maximum peak occurs and this frequency of operation can best be determined with the help of M and N circle.

Answer: a
Explanation: Gain of the open loop system is doubled then the gain of the system is not affected as the gain of the system is not dependent on the overall gain of the system.

Answer: a
Explanation: Nichol’s chart has constant M and N circles that are used to find the stability of the system and the detailed study of their can be determined with the help of the closed loop frequency response.

Answer: d
Explanation: By definition, Constant M loci are Circles of constant phase shift for the closed loop transfer function.

Answer: c
Explanation: Constant N loci are the circles of constant gain for the closed loop transfer function and the intersection point of the M and N is always the point (-1,0).

Answer: b
Explanation: Nichol’s chart are plot of loop gain with the variation in frequency and this is used to determine the stability of the system with the variation in the frequency.