Table of Contents

Toggle**Important RGPV Question**

**EX-405 (Control System)**

**IV Sem, EX**

**UNIT 1 Modelling of Dynamic Systems**

**Q.1** What is a mason gain formula? Explain each component of the formula and mention its advantages over block diagram reduction techniques.

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**Q.2** Obtain the overall transfer function C/R from the signal flow graph shown.

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**Q.3** Determine the transfer function for the block diagram shown in Figure.

Distinguish between Open loop control system and closed loop control system.

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**Q.5** Find the transfer function using Mason’s gain equation.

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**Q.6 **Determine the transfer function X1(s)/F(s) for the system shown below.

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**Q.7** The block diagram of a unity feedback (negative) system is shown in figure. Determine the steady state error for unit ramp input when K-400. Also determine the value of K for which the steady state error to unit ramp will be 0.02.

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**Q.8 **What are open and closed loop transfer system? What are the components of control systems?

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**Q.9** What is Mason’s gain formula? Simplify the given expression and find x5Β / x1

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**Q.10** Write short notes Tacho Generators

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**Q.11** State the advantages and disadvantages of closed loop system.

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**Q.12** Specify the time domain specification.

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**Q.13** State and explain the Mason’s gain formula.

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**Q.14** Derive the transfer function and develop the block diagram of armature control DC servo motor.

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**Q.15 **Write short notes on (any two)

a) Servomotors

b) Potentiometer

c) Steeper motor

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**UNIT 2 Time-domain Analysis of closed loop Systems**

**Q.1** Explain time response of first order system to unit step and unit ramp input. Find the steady state error response for both.

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**Q.2** What are the standard test signals used in time domain analysis, explain each one in detail?

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**Q.3** Discuss the derivative and integral control in detail.

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**Q.4** Explain time response of first order system to unit step and unit ramp input. Find the steady state error response for both.Β

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**Q.5** Discuss the proportional and integral control in detail.

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**Q.6** A unity feedback-system has an open loop transfer function G(s)H(s) Design a phase lag compensator to achieve the followings specifications. Velocity error constants Kv = 5. Phase margin= 45Β°.

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**Q.7** Derive the steady state error for type one system with unit step, ramp and parabolic inputs.

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**Q.8** Consider a type I unit feedback system with an OLTF is specified that Kv = 12 sec-1Β and Ξ¦pmΒ = 40Β°. Design lead compensator to meet the specifications.

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**Q.9** Obtain the steady state erroress of type-0 type-1 and type-2 systems for standard inputs.

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**Q.10** Distinguish between Open loop control system and closed loop control system.

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**Q.11** Name any two compensation techniques employed in the design of control systems.

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**Q.12** Derive the response of second order system with unit step response.

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**Q.13** What is Steady state error? Find the steady state error for a ramp input of a unity feedback control system with open loop transfer function

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**Q.14** Find Kp, Kv, Ka for a system with open loop transfer function as

**input is r(t)=3+t+tΒ².**

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**Q.15** A unity feed back system is characterized by an open loop transfer function G(s)=K/s(s+5). Determine the gain K so that the system will have a damping factor of 0.7. For this value of K determine the natural frequency of the system. It is subjected to a unity step input. Obtain the closed loop response of the system in time domain.

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**Q.16** Derive the expressions for frequency domain specifications of a second order system.

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**Q.17** Given the open loop transfer function of a unity feedback system G(s)=1/5(3+5)(1+2s). Draw the Bode plot and measure from the plot the frequency at which the magnitude is 0 dB.

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**Q.18** What are the standard test signals used in time domain analysis?

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**UNIT 3 Stability**Β

**Q.1** Comment on the stability of the system whose characteristic equation is given by s5+2s4+3s3+68Β²+25+10.

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**Q.2** Sketch the root locus for a system having transfer function

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**Q.3 **Determine the RH stability of given characteristic equation, s4Β + 8s3Β + 18sΒ²+16s + 5=0.

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**Q.4** Sketch the root locus for the unity feedback system whose open loop transfer function is

G(s)H(s) = Β K/ [s (s+4) (sΒ²+4s+20)]

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**Q.5 **Using Routh-Hurwitz criterion determine the relation between K and T so that unity feedback control system whose open loop transfer function given below is stable.

(ii) Determine the modified relation between K and T if all the roots of characteristic equation as determined in (i) are to lie to the left of the line S = -1 in S-plane.

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**Q.6 **What are the important features of open loop control system.

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**Q.7** Derive the expression for steady state error of the closed loop system in terms of generalized error coefficients.

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**Q.8 **Define and derive the breakaway point on the root locus.

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**Q.9 **Explain Routh-Hurwitz stability analysis.

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**Q.10** Discuss on stability of Root Locus.

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**Q.11** Give basics steps for construction of Root Locus.

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**Q.12** Explain the Routh’s criteria with an example. What are its limitations?

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**Q.13** Determine the stability of the closed loop system whose open loop transfer is 5(2s+1)/s(s+1)(1+3s) (1+0.5s), using Routh-Hurwitz criterion.

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**Q.14** What are the advantages of root locus?

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**Q.15** Explain the procedure to draw root locus of a given transfer function.

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**UNIT 4 Frequency**Β

**Q.1** Consider the following polar plot shown in Figure below. If now a pole at origin and a pole at s-1/T2Β are added, sketch the polar plot.

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**Q.2** Sketch the bode plot for the following transfer function and determine phase margin and gain margin.

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**Q.3** Draw the polar plot for open loop transfer function for unity feedback system.

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**Q.4 **State and explain Nyquist stability criteria.

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**Q.5 **Consider the following polar plot shown in Figure below. If now a pole at origin and a pole at s=-1/T2Β are added, sketch the polar plot.

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**Q.6** Describe the procedure for developing the polar plot

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**Q.7** Draw the Nyquist plot for the system whose open loop transfer function is

G(s)H(s) = K/[s(s+2) (s+10)] Determine the range of K for which the closed loop system is stable.

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**Q.8 **Sketch the bode plot for the following transfer function and determine phase margin and gain margin.

G(s) = 75 (1+0.2s)/[s (sΒ²+16s+100)]

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**Q.9** Define the following terms:

i) Settling time and relative stability

ii) phase margin and gain margin.

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**Q.10** Test the stability of the unity feedback system G when K=10 using Nyquist criterion and then find the range of K for stability.

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**Q.11** Explain in detail about Gain and Phase Margins.

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**Q.12** For a closed loop control system G(s)= 100 / s(s + 8), H(s) = 1. Determine the resonant peak and resonant frequency.

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**Q.13 **Draw Polar plot of

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**Q.14** Write short notes Nyquist stability analysis

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**Q.15** State and prove Nyquist stability theorem.

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**UNIT 5 Design of Control System**Β

**Q.1** What is lag-lead compensator? Under what conditions it is employed? Explain.

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**Q.2** Obtain the solution of state equation and list the properties of state transition matrix.

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**Q.3** Write a short notes on Eigen values and Eigen vectors

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**Q.4** Draw the electrical circuit diagram that represents the Lead-Lag compensator and explain in detail.

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**Q.5** Given the state equations below, write the transfer function for this system. Assume the output variable in the transfer function is y(t) which is equal to the state variable x1.

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**Q.6** Derive an expression for peak time tp of an underdamped second order systems subjected to step input.

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**Q.7** Write short notes on:

i) Need of compensator

ii) Asymptotes

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**Q.8** Derive the expression of transfer function of lead compensator. What are the effects of phase lead compensation?

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**Q.9** What is Lag-Lead compensator?

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**Q.10 **Find the state transition matrix for

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**Q.11 **What are Servomotors (AC and DC)?

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**Q.12** What are Proportional and Derivative controller.

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**Q.13** Write short notesΒ PID controllers

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**Q.14** Discuss the effect of PD and PI on performance of a control system.

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**— Best of Luck for Exam —**