STUPIDSID
Do as directed (short questions)
1(a)
List out the features of negative feedback in a closed loop system.
1 M
1(b)
What is steady-state error?
1 M
1(c)
Define pole, zero and order of a control system.
1 M
1(d)
What are the advantages of state space analysis?
1 M
1(e)
Draw the block diagram/signal flow graph representation of the system described by the state model \( \begin{bmatrix}
x_1\\
x_2\\
x_3
\end{bmatrix}=\begin{bmatrix}
a_1 & a_2 & 0\\
1 & 0 & 1\\
0 & 1 & 0
\end{bmatrix}\begin{bmatrix}
x_1\\
x_2\\
x_3
\end{bmatrix}+\begin{bmatrix}
1\\
0\\
0
\end{bmatrix}u\ \text{and}\ y=x_3. \)
1 M
1(f)
The closed loop transfer function of a second order system is given by \( \dfrac{200}{s^2+20s+200} \). Determine the damping ratio and natural frequency of oscillation.
1 M
1(g)
What is polar plot? Draw the polar plot of G(s) = 1/(1 + sT).
1 M
1(h)
With graphical representation, explain How the roots of characteristic equation are related to stability?
1 M
1(i)
What is Nyquist stability criterion?
1 M
1(j)
How will you find the gain K at a point on root locus?
1 M
1(k)
Sketch the frequency response (bode) plot of G(s) = 1/(1 + sT).
1 M
1(l)
What is the effect on system performance, when a proportional
controller is introduced in a system?
1 M
1(m)
State the transfer function of lead compensator and draw its pole-zero plot.
1 M
1(n)
What is PD-Controller and what are its effect on system performance?
1 M
2(a)
For the given mechanical translation system as shown in Fig. 1. Write down differential equations, represents in Force-Voltage analogy.
3 M
2(b)
Obtain the state space representation of armature controlled DC motor with load. Consider armature current ia , the angular displacement of shaft θ , and the speed dθ/dt as state variables, and θ as output variable.
4 M
Solve any one question from Q.2(c) & Q.2(d)
2(c)
A linear feedback control system has the block diagram shown in Fig. 2. Using block diagram reduction rules, obtain overall transfer function C(s)/R(s) .
7 M
2(d)
For the signal flow graph shown in Fig. 3, using Masson's gain formula determine the overall transmission C/R.
7 M
Solve any three question from Q.3(a), Q.3(b), Q.3(c) & Q.3(d), Q.3(e), Q.3(f)
3(a)
Define thermal resistance and thermal capacitance. Also derive the transfer function of Thermometer placed in water bath as a Thermal system.
3 M
3(b)
Find the position, velocity and acceleration error constants, for a unity feedback control system has the open loop transfer function G(s) = 10(s+2)/s2(s+1).
4 M
3(c)
Obtain the state model and give block diagram representation for a
system whose closed-loop transfer function is given as, \[\dfrac{Y(s)}{U(s)}=\dfrac{10(s+4)}{s(s+1)(s+3)}\]
7 M
3(d)
Using suitable diagram derive the transfer function of liquid level
system with interaction.
3 M
3(e)
A unity feedback system has a open loop transfer function of \( G(s)=\dfrac{20(s+5)}{s(s+0.1)(s+3)} \). Determine the steady-state error for parabolic input.
4 M
3(f)
The open-loop transfer function of a unity feedback system is given by G(s) = K/s (sT+1). where K and T are positive constant. By what factor should the amplifier gain K be reduced, so that the peak overshoot of unit step response of the system is reduced from 75% to 25%.
7 M
Solve any three question from Q.4(a), Q.4(b), Q.4(c) & Q.4(d), Q.4(e), Q.4(f)
4(a)
State advantages and limitations of Routh's stability criterion.
3 M
4(b)
Using R-H criterion determine the relation between K and T so that
unity feedback control system whose open-loop transfer function given is stable \( G(s)=\dfrac{K}{s[s(s+10)+T]}. \)
4 M
4(c)
Investigate the stability of a closed-loop system whose open-loop transfer function is \( G(s)H(s)=\dfrac{5}{s(1+5s)} \) using Nyquist stability criterion.
7 M
4(d)
What do you understand by absolute stability and relative stability? Which method indicates what type of stability?
3 M
4(e)
Explain, How the gain and phase margin are obtained from Nyquist
Plots?
4 M
4(f)
Draw the Bode plot for a system having \( G(s)H(s)=\dfrac{100}{s(s+1)(s+2)}. \) Find out Gain margin, Phase margin, Gain crossover frequency and phase cross over frequency.
7 M
Solve any three question from Q.5(a), Q.5(b), Q.5(c) & Q.5(d), Q.5(e), Q.5(f)
5(a)
What is breakaway and breakin point? How to determine them?
3 M
5(b)
Determine the relation between the phase margin and damping ratio for an underdamped second-order system.
4 M
5(c)
Sketch the root locus of the system whose open-loop transfer function is \( G(s)=\dfrac{K}{s(s+2)(s+4)}. \) Find the values of K so that the damping ratio of the closed-loop system is 0.5.
7 M
5(d)
How will you obtain the transfer function from Bode magnitude plot?
3 M
5(e)
What is lag compensator? With respect to the electrical equivalent phase-lag compensator state the transfer function, draw its pole-zero plot, and the bode plot of lag compensator.
4 M
5(f)
Design suitable lead compensator for a system with unity feedback and having open-loop transfer function \[G(s)=\dfrac{K}{s(s+8)}.\]
to meet the following specifications:
(i) Percentage peak overshoot = 9.5%
(ii) Natural frequency of oscillation, ωn = 12 rad / sec
(iii) Velocity error constant, Kv ≥ 10.
to meet the following specifications:
(i) Percentage peak overshoot = 9.5%
(ii) Natural frequency of oscillation, ωn = 12 rad / sec
(iii) Velocity error constant, Kv ≥ 10.
7 M
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