1 (a)
Distinguish between open loop and closed loop system with examples.
6 M
1 (b)
Write the differential equations of performance for the mechanical system shown in Fig. Q1 (b). Draw its F-V analogous circuit.
6 M
1 (c)
Obtain the transfer function of an armature controlled DC servomotor.
6 M
2 (a)
Obtain the transfer function of the block diagram shown below, using block diagram reduction technique.
10 M
2 (b)
Obtain the closed loop transfer function C(s)/R(s) for the signal flow graph of a system shown in Fig. Q2(b) by use of Mason's gain formula.
10 M
3 (a)
Derive expression for peak response time tp and maximum overshoot Mp of an under damped second order control system subjected to step input.
6 M
3 (b)
A second order control system is represented by a transfer function given below: \[ \dfrac {0_0(s)}{T(s)}= \dfrac {1}{Js^2+Fs+K} \] where ?0 is the proportional output and T is the input torque. A step unit of 10 N-m is applied to the system and test results are given below:
i) Maximum overshoot is 6%
ii) Peak time is 1 sec
iii) The steady state value of the output is 0.5 radian.
Determine the values of J, F and K.
i) Maximum overshoot is 6%
ii) Peak time is 1 sec
iii) The steady state value of the output is 0.5 radian.
Determine the values of J, F and K.
8 M
3 (c)
For a unity feedback control system with \[ G(s)= \dfrac {10(s+2)}{s^2 (s+1)} \] find:
i) The static error coefficients
ii) Steady state error when the input transform is \[ R(s)= \dfrac {3}{s}- \dfrac {2}{s^2}- \dfrac {1}{3s^2} \]
i) The static error coefficients
ii) Steady state error when the input transform is \[ R(s)= \dfrac {3}{s}- \dfrac {2}{s^2}- \dfrac {1}{3s^2} \]
6 M
4 (a)
Explain Routh-Hurwitz's criterion for determining the stability of a system and mention any three limitations of R-H criterion.
10 M
4 (b)
A unity feedback control system is characterized by the open loop transfer function: \[ G(s) = \dfrac {K(s+13)} {s(s+3)(s+7)} \] i) Using the Routh's criterion, calculate the range of values of K for the system to be stable.
ii) Check if for K=1, all the roots of the characteristic equation of the above system are more negative than -0.5.
ii) Check if for K=1, all the roots of the characteristic equation of the above system are more negative than -0.5.
10 M
5 (a)
Sketch the root locus for a unity feedback control system with open loop transfer function: \[ G(s)= \dfrac {K(s+2)(s+3)}{s(s+1)} \]
12 M
5 (b)
Show that the root Loci for unity feedback control system with \[ G(s)=\dfrac {K(s^2 +6s +10)}{(s^2+2s+10)} \] are the areas of circle of radius √10 and centred at the origin.
8 M
6 (a)
Sketch the Bode plot of a unity feedback system whose open loop transfer function is given by \[ G(s)= \dfrac {K}{s(1+0.1s)(s+0.05s)} \] i) Find the value of K for a gain margin of 10dB.
ii) Find the value of K for a phase margin of 30°.
ii) Find the value of K for a phase margin of 30°.
14 M
6 (b)
Determine the open loop transfer function of a system whose approximate plot is shown below.
6 M
7 (a)
State and explain Nyquist stability criterion.
6 M
7 (b)
Sketch the Nyquist plot for a system whose open loop transfer function is \[ G(s)H(s)= \dfrac {K(4s+1)}{s(2s-1)} \] Determine the range of K for which the system is stable.
14 M
8 (a)
Define state variable and state transition matrix. List the properties of the state transition matrix.
8 M
8 (b)
Obtain the state model of the electrical network shown in below, by choosing V1(t) and V2(t) as state variables.
12 M
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