GATE ECE
Control Systems
Frequency Response Analysis
Previous Years Questions

## Marks 1

Consider a closed-loop control system with unity negative feedback and KG(s) in the forward path, where the gain K = 2. The complete Nyquist plot of t...
The number and direction of encirclements around the point −1 + j0 in the complex plane by the Nyquist plot of G(s) =$${{1 - s} \over {4 + 2s}}$$ is
A closed-loop control system is stable if the Nyquist plot of the corresponding open-loop transfer function
Consider the Bode plot shown in the figure. Assume that all the poles and zeroes are real-valued. The value of fH - fL (in Hz) is ______. ...
The phase margin (in degrees) of the system G(s)=$${{10} \over {\left( {s + 10} \right)}}$$ is ___________.
The popular plot of the transfer function G(s)=$${{10\left( {s + 1} \right)} \over {\left( {s + 10} \right)}}$$ for $$0 \le \omega < \infty$$ wil...
In a Bode magnitude plot, which one of the following slopes would be exhibited at high frequencies by a 4th order all-pole system?
Consider the feedback system shown in the figure. The Nyquist plot of G(s) is also shown. Which one of the following conclusions is correct? ...
The Bode plot of a transfer function G (s) is shown in the figure below. The gain (20 log $$\left| {G(s)} \right|$$ ) is 32 dB and -8dB at 1rad/s ...
A system with transfer function g(s) = $${{\left( {{s^2} + 9} \right)\left( {s + 2} \right)} \over {\left( {s + 1} \right)\left( {s + 3} \right)\left... For the transfer function G$$\left( {j\omega } \right) = 5 + j\omega ,$$the corresponding Nyquist plot for positive frequency has the form A system with the transfer function$${{Y(s)} \over {X(s)}} = {s \over {s + p}},$$has an output y(t)=$$\cos \left( {2t - {\pi \over 3}} \right),$$... For the asymptotic Bode magnitude plot shown below, the system transfer function can be ... If the closed-loop transfer function of a control system is given as T(s)=$${{s - 5} \over {(s + 2)(s + 3)}},$$then it is The open-loop transfer function of a unity-gain feedback control system is given by$$G(s) = {K \over {(s + 1)(s + 2)}},$$the gain margin of the syst... In the system shown below, x(t)=(sin t). In steady-state, the response y(t) will be ... Which one of the following polar diagrams corresponds to a lag network? Figure shows the Nyquist plot of the open-loop transfer function G(s)H(s) of a system. If G(s)H(s) has one right hand pole, the closed loop system is ... The gain margin for the system with open-loop transfer function G(s)H(s)=$${{2(1 + s)} \over {{s^2}}}$$is The phase margin of a system with the open-loop transfer function G(s)H(s)=$${{(1 - s)} \over {(1 + s)(2 + s)}}$$is? The Nyquist plot for the open-loop transfer function G(s) of a unity negative feedback system is shown in figure. if G(s) has no pole in the right hal... The gain margin of a system having the loop transfer function G(s)H(s) =$${{\sqrt 2 } \over {s(s + 1)}}$$is The phase margin (in degrees) of a system having the loop transfer function is$$G(s)H(s) = {{2\sqrt 3 } \over {s(s + 1)}}$$In the Bode-plot of a unity feedback control system, the value of phase of G($$j\omega $$) at the gain cross over frequency is$$ - 125^\circ $$. The ... The Nyquist plot of a loop transfer function G$$(j\omega )$$H$$(j\omega )$$, of a system encloses the (-1, j0) point. The gain margin of the system i... Non - minimum phase transfer function is defined as the transfer function The 3-dB bandwidth of a typical second- order system with the transfer function$${{C\left( s \right)} \over {R(s)}} = {{\omega _n^2} \over {{s^2} + 2...
The open loop frequency response of a system at two particular frequencies are given by: 1.2 $$\angle - 180^\circ$$ and 1.0 $$\angle - 190^\circ ... ## Marks 2 The figure below shows the Bode magnitude and phase plots of a stable transfer function$$G(s) = {{{n_0}} \over {{s^3} + {d_2}{s^2} + {d_1}s + {d_0}}}...
For a unity feedback control system with the forward path transfer function $$G(s) = {K \over {s\left( {s + 2} \right)}}$$ The peak resonant magnitude...
A unity feedback control system is characterized by the open loop transfer function $$G(s) = {{10k\left( {s + 2} \right)} \over {\left( {{s^3} + 3{s^... The Nyquist plot of the transfer function$$G(s) = {k \over {\left( {{s^2} + 2s + 2} \right)\left( {s + 2} \right)}}$$does not encircle the point (-... In the feedback system shown below$${\rm{G(s) = }}{1 \over {\left( {s + 1} \right)\left( {s + 2} \right)\left( {s + 3} \right)}}$$The positive ... The asymptotic Bode phase plot of$${\rm{G(s) = }}{k \over {\left( {s + 0.1} \right)\left( {s + 10} \right)\left( {s + {p_1}} \right)}},$$with k an... The transfer function of a mass-spring damper system is given by$${\rm{G(s) = }}{1 \over {M{s^2} + Bs + K}}$$The frequency response data for the sy... The Bode asymptotic magnitude plot of a minimum phase system is shown in the figure. If the system is connected in a unity negative feedback config... The phase margin in degrees of G(s)=$${{10} \over {\left( {s + 0.1} \right)\left( {s + 1} \right)\left( {s + 10} \right)}},$$using the asymptotic Bo... The input-output transfer function of a plant is h(s)=$${{100} \over {s{{\left( {s + 10} \right)}^2}}}$$. The plant is placed in a unity negative feed... The input-output transfer function of a plant is h(s)=$${{100} \over {s{{\left( {s + 10} \right)}^2}}}$$. The plant is placed in a unity negative feed... The Nyquist plot of a stable transfer function G(s) is shown in the figure. We are interested in the stability of the closed loop system in the feedba... The Nyquist plot of a stable transfer function G(s) is shown in the figure. We are interested in the stability of the closed loop system in the feedba... The impulse response h(t) of a linear time invariant system is given by h(t) =$${e^{ - 2t}}u(t),$$where u(t) denotes the unit step function. The fre... The magnitude of frequency response of an underdamped second order system is 5 at 0 rad/sec and peaks to$${{10} \over {\sqrt 3 }}$$at 5$$\sqrt 2 $$... The impulse response h(t) of a linear time invariant system is given by h(t) =$${e^{ - 2t}}u(t),$$where u(t) denotes the unit step function. The ou... The asymptotic Bode plot of a transfer function is shown in the figure. the transfer function G(s) corresponding to this bode plot is ... Consider two transfer functions$${G_1}\left( s \right) = {1 \over {{s^2} + as + b}}$$and$${G_2}\left( s \right) = {s \over {{s^2} + as + b}}.$$Th... The Nyquist plot of G(jω)H(jω) for a closed loop control system, passes through (-1,j0) point in the GH plane. The gain margin of the system in dB is ... Consider a unity-gain feedback control system whose open-loop transfer function is G(s)=$${{as + 1} \over {{s^2}}}$$. With the value of "a" set for p... Consider a unity-gain feedback control system whose open-loop transfer function is G(s)=$${{as + 1} \over {{s^2}}}$$The value of 'a', so that the s... The open loop transfer function of a unity feedback system is given by g(s)=$${{3{e^{ - 2s}}} \over {s\left( {s + 2} \right)}}.$$Based on the above ... The polar diagram of a conditionally stable system for open loop gain K=1 is shown in figure. The open loop transfer function of the system is known t... The open loop transfer function of a unity feedback system is given by G(s)=$${{3{e^{ - 2s}}} \over {s\left( {s + 2} \right)}}.$$The gain and phase... Consider the Bode magnitude plot shown in figure. The transfer function H(s) is ... A system has poles at 0.01 Hz, 1Hz and 80 Hz; zeroes at 5hz, 100 Hz and 200 Hz. The approximate phase of the system response at 20 Hz is The approximate Bode magnitude plot of a minimum-phase system is shown in figure. The transfer function of the system is ... The gain margin and the phase margin of a feedback system with G(s)H(s)=$${s \over {{{\left( {s + 100} \right)}^3}}}$$are The system with the open loop transfer function G(s)H(s)=$${1 \over {s\left( {{s^2} + s + 1} \right)}},$$has a gain margin of The open-loop DC gain of a unity negative feedback system with closed-loop transfer function$${{s + 4} \over {{s^2} + 7s + 13}}$$is Bode plot of a stable system is shown in fig. The transfer function of the system is ... The open-loop transfer function of a feedback control system is G(s)=$${1 \over {{{\left( {s + 1} \right)}^3}}}$$The gain margin of the system is From the Nicholas chart, one can determine the following quantities pertaining to a closed loop system: A system has fourteen poles and two zeroes. Its high frequency asymptote, in its magnitude plot, has having a slope of The popular plot of G(s)=$${{10} \over {s{{\left( {s + 1} \right)}^2}}},$$intercepts real axix at$$\omega = {\omega _0}$$Then, the real part and ... ## Marks 5 The Nyquist plot of an all-pole second order open-loop system is shown in Figure. Obtain the transfer function of the system. ... The asymptotic bode plot of the minimum phase open-loop transfer function G(s)H(s) is as shown in the figure. Obtain the transfer function G(s)H(s) ... Consider a feedback system with the open loop transfer function given by$$G(s)H(s) = {K \over {s\left( {2s + 1} \right)}}.$$Examine the stability of... The loop transfer function of a single loop control system is given by$$G(s)H(s) = {{100} \over {s\left( {1 + 0.01s} \right)}}{e^{ - ST}}$$Using Ny... ## Marks 8 A unity feedback system has open-loop transfer function$$G(s) = {1 \over {s\left( {2s + 1} \right)\left( {s + 1} \right)}}$$Sketch Nyquist plot for... The magnitude plot of the open loop transfer function G(s), of a certain system is given in fig, (a) Determine G(s), if it is known that the system i... ## Marks 10 Nyquist plot consider a feed back system where the OLTF is:$$G(s) = {1 \over {s\left( {2s + 1} \right)\left( {s + 1} \right)}}. Determine the asym...
EXAM MAP
Joint Entrance Examination