## Download Previous Year PTU University QuestionÂ Paper of Linear Control Systems 4th Sem BTEE-402 B.Tech EE PTU APRIL 2013 Paper

**B.Tech.** **(EE-2011 Batch)**

## LINEAR CONTROL SYSTEMS

### Subject Code : BTEE-402Â Â Â Â Â Paper ID : [ A1188]

### Time : 3 Hrs.Â Â Â Â Â Â Â Â Â Â Â Â Â Max. Marks : 60

#### INSTRUCTIONS TO CANDIDATES :

1. SECTION-A is COMPULSORY consisting of TEN questions carrying TWO marks each.

2. SECTION-B contains FIVE questions carrying FIVE marks each and students have to attempt any FOUR questions.

3. SECTION-C contains THREE questions carrying TEN marks each and students have to attempt any TWO questions

## Linear Control Systems 4th Sem BTEE-402 B.Tech EE PTU Nov 2018 Paper

**SECTION-A**

**Q1. Write Short Notes on :**

#### a) What is the difference between closed loop and open loop system?

#### b) What is the difference between reference signal and actuating signal?

#### c) What is the difference between relative and absolute stability?

#### d) What are the minimal and non-minimal phase functions?

#### e) What is steady state error?

#### f) Draw and explain the transfer characteristics of a potentiometric error detector.

g) What is the difference between automatic regulator and servomechanism?

#### h) What do you mean by critical damping?

#### i) Define gain cross-over and phase cross-over frequency.

#### j) Draw schematic diagram of Position Control System.

## Â **Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â SECTION-B**

**Q2. Attempt any FOUR questions.Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 5×4=20**

#### 2. How do you complete the Routhâ€™s array.

a) If the elements of first column comes out to be zero.

b) If all the elements in a row are zero.

3. What is Massonâ€™s Gain formula used for finding transfer function in signal flow graph? Explain with the help of an example.

4. For a unity feedback system whose open loop transfer function is

*G*(*s*) =50/(1 + 0.1*s*)(1 + 2*s*)

#### Find the position, velocity and acceleration error constants.

#### 5. Explain the procedure how to draw magnitude & phase versus frequency plot and how to determine gain margin and phase margin from the plot?

6. Distinguish between Transfer function and state space representation of a linear time invariant system and hence define the state transition matrix with its importance in system study.

**Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â SECTION-C**

**Q3. Attempt any TWO questions.****Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 2×10=20**

#### 2.Construct the root locus for the given system explaining the

#### Find the range of gain *K *> 0 for which the closed loop system is stable

*KG*(*s*)*H* (*s*) =*K/**s* (*s* + 2)Â (*s*2Â Â + 2*s *+ 37)

#### 3.The open loop transfer function of a servo system is

*G*(*s*) =64(*s *+ 2)/*s *(*s *+ 0.5) (*s*2 + 3.2*s *+ 64)

#### Draw the Bode plot of the system and determine the gain margin and phase margin there from.

#### 4.(a) Explain the working of an error detector cum transducer suitable for angular displacement of 0 degree to 360

#### (b) Mention the special characteristics of a servo motor. Also derive the transfer function of a field controlled d.c. servo motor. State the various assumptions taken.

Difference between closed loop and open loop system.

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Difference between reference signal and actuating signal.

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Difference between relative and absolute stability.

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Minimal and non-minimal phase functions.

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Steady state error.

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Transfer characteristics of a potentiometric error detector.

Difference between automatic regulator and servomechanism.

Â

Critical damping.

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Gain cross-over and phase cross-over frequency.

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Schematic diagram of Position Control System.

###### Linear Control Systems 4th Sem BTEE-402 B.Tech PTU APRIL 2013 PaperÂ

Routhâ€™s array.

a) If the elements of first column comes out to be zero.

b) If all the elements in a row are zero.

Massonâ€™s Gain formula used for finding transfer function in signal flow graph.

For a unity feedback system whose open loop transfer function is

*G*(*s*) =50/(1 + 0.1*s*)(1 + 2*s*)

Find the position, velocity and acceleration error constants.

Â

Procedure how to draw magnitude & phase versus frequency plot

Determine gain margin and phase margin from the plot.

Transfer function and state space representation of a linear time invariant system

state transition matrix with its importance in system study.