Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 4th Sem 2141004 Control System Engineering Previous Question Paper

Enrolment No.___________

**GUJARAT TECHNOLOGICAL UNIVERSITY**

**BE - SEMESTER? IV EXAMINATION ? SUMMER 2020**

**Subject Code: 2141004**

**Date:29/10/2020**

**Subject Name: CONTROL SYSTEM ENGINEERING**

**Time: 10:30 AM TO 01:00 PM**

**Total Marks: 70**

**Instructions:**

**1. Attempt all questions.**

**2. Make suitable assumptions wherever necessary.**

**3. Figures to the right indicate full marks.**

Q.1 a. Draw the equivalent mechanical system for the system shown in figure 1. 3

Also write the set of equilibrium equations for it.

*Figure 1*

b. Define the following terms:

4

1. Transfer function.

2. Characteristic equation.

3. Order of the system.

4. Type of the system.

c. Discuss open loop control system and closed loop control system with 7

suitable examples.

Q.2 a. In F-V analogy

3

1. Mass is analogous to__________.

2. Friction is analogous to ________.

3. Spring of c

onstant k is analogous to __________.

b. Explain Mason's Gain Formula.

4

c. Determine the transfer function for the system shown in figure 2.

7

*Figure 2*

**OR**

c. Obtain the block diagram for the electrical network shown in figure 3.

7

*Figure 3*

Q.3 a. Define the following test signals.

3

1. Unit Impulse

2. Unit Step

3. Unit Ramp

b. Discuss the effect of feedback on system gain and stability.

4

c. Derive the expression of a second order control system subjected to unit 7

step signal.

**OR**

Q.3 a. Define the following terms with respect to a second order system subjected

3

to unit step signal.

1. Rise time

2. Peak time

3. Settling time

b. Discuss the effect of adding a pole to a closed loop transfer function.

4

c. Derive the expressions for error constants Kp , Kv and Ka corresponding 7

to step, ramp and parabolic input respectively.

Q.4 a. 1. In a system, for a bounded input output is also bounded. The system is said 3

to be ____________.

2. In a system, two poles are on the negative real axis and one pair of poles

lies on j axis. The system is said to be__________.

3. In a system, repeated roots are placed on imaginary axis. The system is said to be

__________.

b. State advantages and limitations of Routh's stability criterion

4

c.

4

7

For a unity feedback system

*G*(

*s*)

,the system is marginally

2

*s*(

*s*

*qs*2

*k*)

stable and oscillates with frequency 4 rad/sec. Find kmar and q.

**OR**

Q.4 a. Define the following terms:

3

1. Stable system

2. Unstable system

3. Marginally stable system

b. Discuss Hurwitz's stability criteria.

4

c. Explain the r

ules for the construction of Root Locus.

7

Q.5 a. Discuss briefly PID controller.

3

b. Discuss Nyquist criteria for stability.

4

c. A second order system has overshoot of 50% and period of oscillations 0.2 7

second in step response. Determine resonant peak and resonant frequency.

**OR**

Q.5 a. Compare time response and phase response of the system.

3

b. Define the following with respect to Bode Plot:

4

1. Gain cross over frequency

2. Phase cross over frequency

3. Gain Margin

4. Phase Margin

c. Write a short note on state space representation of a control system.

7

*****

This post was last modified on 04 March 2021