## Download Previous Year PTU University Question 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-402 Paper ID : [ A1188]

### Time : 3 Hrs. 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.

## ** SECTION-B**

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

#### 2. How do you complete the Routh’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 Masson’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.

** SECTION-C**

**Q3. Attempt any TWO questions.**** 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) (*s*2 + 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.

Difference between reference signal and actuating signal.

Difference between relative and absolute stability.

Minimal and non-minimal phase functions.

Steady state error.

Transfer characteristics of a potentiometric error detector.

Difference between automatic regulator and servomechanism.

Critical damping.

Gain cross-over and phase cross-over frequency.

Schematic diagram of Position Control System.

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

Routh’s array.

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

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

Masson’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.

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.