objective question paper

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6. Previous years question papers JNTUA

CONTROL SYSTEMS

Syllabus

JAWAHARLAL NEHRU

TECHNOLOGICAL UNIVERSITY ANANTAPUR

B.Tech III-I Sem. (E.E.E) T P C

4 0 4

(9A02503) CONTROL SYSTEMS

(Common to EEE, ECE, E Con E, EIE)

Objective:In this course it is aimed to introduce to the students the principles and applications of control systemsin everyday life. The basic concepts of block diagram reduction, time domain analysis solutions to timeinvariant systems and also deals with the different aspects of stability analysis of systems in frequencydomain and time domain.

UNIT I INTRODUCTIONConcepts of Control Systems- Open Loop and closed loop control systems and their differences-Examples of control systems- Classification of control systems, Feed-Back Characteristics, Effects offeedback. Mathematical models Differential equations, Impulse Response and transfer functions -Translational and Rotational mechanical systems

UNIT II TRANSFER FUNCTION REPRESENTATION


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Transfer Function of DC Servo motor - AC Servo motor- Synchro transmitter and Receiver -Block diagramalgebra Signal flow graph - Reduction using Masons gain formula.

UNIT-III TIME RESPONSE ANALYSIS

Standard test signals - Time response of first order systems Characteristic Equation of Feedbackcontrol systems, Transient response of second order systems - Time domain specifications Steady stateresponse - Steady state errors and error constants Effects of proportional, integral, derivative Controls.

UNIT IV STABILITY ANALYSIS IN S-DOMAINThe concept of stability Rouths stability criterion qualitative stability and conditional stability limitations of Rouths stability. The root locus concept - construction of root loci-effects of adding polesand zeros to G(s)H(s) on the root loci.

UNIT V FREQUENCY RESPONSE ANALYSISIntroduction, Frequency domain specifications-Bode diagrams-Determination of Frequency domainspecifications and transfer function from the Bode Diagram-Phase margin and Gain margin-StabilityAnalysis from Bode Plots.

UNIT VI STABILITY ANALYSIS IN FREQUENCY DOMAINPolar Plots-Nyquist Plots-Stability Analysis.

UNIT VII CLASSICAL CONTROL DESIGN TECHNIQUESCompensation techniques Lag, Lead, Lead-Lag Controllers design in frequency Domain, P, PD, PI, PIDControllers.

UNIT VIII STATE SPACE ANALYSIS OF CONTINUOUS SYSTEMSConcepts of state, state variables and state model, derivation of state models from block diagrams,Diagonalization- Solving the Time invariant state Equations- State Transition Matrix and its Properties.

TEXT BOOKS:1. Automatic Control Systems by B. C. Kuo and Farid Golnaraghi John wiley and sons, 8th edition,

2003.

2. Control Systems Engineering by I. J. Nagrath and M. Gopal, New Age International (P) Limited,Publishers, 5 th edition, 2007.

3. Control Systems A. Anand Kumar, Prentice Hall of India Pvt. Ltd.,


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REFERENCE BOOKS:

1. Modern Control Engineering by Katsuhiko Ogata Prentice Hall of India Pvt. Ltd., 5 th edition, 2010.2. Control Systems Engineering - by NISE 5 th Edition John wiley.3. Modelling & Control Of Dynamic Systems by Narciso F. Macia George J. Thaler, Thomson

Publishers.4. Modern Control Engineering by Yaduvir Singh and S. Janardhan, CENGAGE Learning.

Objective

Objective:

In recent years, control systems have assumed an increasingly important role in thedevelopment and advancement of modern civilization and technology. Practically every aspect of ourday-to-day activities is affected by some type of control systems.

Control systems are found in abundance in all sectors of industry, such as equality control ofmanufactured products, automatic assembly line, machine-tool control, space technology and weaponsystems, computer control, transportation systems, power systems, robotics, Micro Electro Mechanicalsystems (MEMS), nano technology and many others.

In this subject it is aimed to introduce to the students the principles and application of controlsystems in everyday life. The basic concepts of block diagram reduction, time domain analysis solutionsto time invariant systems and also deals with the different aspects of stability analysis of systems infrequency domain and time domain.


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Lesson Plan

PBR VISVODAYA INSTITUTE OF TECHNOLOGY AND SCIENCE: KAVALI

LESSON PLAN

Year : 2012 2013 Branch: EEE-A Class : III BTech / Isem

Faculty : P.Srihari Subject : CONTROL SYSTEMS

S.No. DatesPeriods

per weekTopic to be covered

No.of

Periods

required

Total

Periods

Per unit

1 5

Unit 1

Introduction, examples of control systems

Open loop and closed loop control systems

Classification of control systems

Definition of transfer function and mathematical models

1

1

1

2

10

25

Impulse response

Translational and rotational mechanical systems andanalogies

1


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Feed back characteristics and effects 2

2

3 5

Unit-2

Transfer function of DC & Ac servo motor

Synchro transmitter and receiver

Transfer functions of other systems

2

1

2

10 4 5

Block diagram algebra- reduction technics

Problems

Advantages of Signal flow graph

Reduction of SFG by using Masons gain formula -Problems on SFG

2

1

2

5 5

Unit-3

Standard Test signals time response of 1 ST orderSystems

CE of feedback control systems, Transient response of 2 nd order systems

Time domain specifications- Steady state response

1

2

2

9

6. 4

Steady state errors and error constants and problems

Effects of Proportional, derivative control

Proportional integral controller, PID controller

1

1

2

7. 4

Unit-4

Concept of stability- Rouths criterion & problems

Qualitative and conditional stability & limitations toRouths criterion

2

2 9

8. 4

Root locus concept construction of Root loci

Problems on root locus

Effects of addition of poles and zeros

2

2


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1

9. 5 Revision of 1-4 chapters and important bits 5 5

3/9/12 To 5/9/12 I MID exams

10 2

Unit-5

Introduction to frequency response analysis

Frequency domain specifications

1

1

9

11 5

Bode diagrams procedure

Transfer fuction gain margin and phase margin fromBode plots

Stability analysis from Bode plots

1

2

2

12

4

Problems on Bode plot

Unit-6

Polar plots & problems on polar plots

Nyquist plots introduction, Theory regarding Nyquist plots

2

1

1

6

13 5

Problems on Nyquist plots

Stability analysis using Nyquist plots

Unit-7

Compensation techniques lag & lead

2

2

1


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14

4 Problems on lag, lead compensators

Lead-lag controllers in frequency domain

P,PI Controllers

2

1

1

6

15

5

PD, PID Controllers

Unit-8

State space analysis- concepts of state

State variables state model

Derivation of state models from block diagrams

Diagonalisation Solution to time invariant stateequations

1

1

1

1

1

8

16 5

State transition matrix and its properties problems onobtaining state transition matrix

Controllability and observability

1

2

1

17 2 Revision of previous model papers and important topics 2 2

18 3 Revision for II- MID 3 3

Total 77 77


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FACULTY SIGNATURE HOD SIGNATURE

Total


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Question Papers Mid-semester examinations

P R Visvodaya Institute of Technology and Science

Class: III B.Tech .I-Sem. Branch: EEEI MID (Objective)

Subject: CONTROL SYSTEMS

Max Marks: 10 Time: 20 MIN Date: 04/09/2012(AN)

NAME: ROLL NO:

Answer all Questions

1. The transfer function of a system is the Laplace transform if its [ ](a) ramp response (b) impulse (c) square wave (d) step

2. In force-voltage analogy, mass equal in electrical system [ ]

(a) voltage (b) capacitance (c) inductance (d) resistance

3. In force-current analogy, dashpot equal in electrical system [ ]

(a)voltage (b) capacitance (c)conductance (d) resistance

4. Applied force equal to opposing forces. It is called ________ law [ ]

(a) Newtons first law (b) newtons second law (c) newtons third law (d)KVL

5. AC servo motor is a [ ](a)open loop CS (b) closed loop CS (c) mixed loop CS (d) None

6. The time that it takes to settle to the final value is called [ ](a) Steady state (b) transient state (c) both (d) None

7. The time domain specification which is dependent only on the damping factor is [ ](a)Rise time (b)peak time (c)settling time (d) peak overshoot

8. Root locus diagram can be used to determine [ ]

(a) Conditionally stability (b) absolute stability (c) relative stability (d) none

9. The value of K for which the system s^3+3S^2+3S+1+K=0 become stable is [ ]


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(a) K=8 (b) K=7 (c) K>7 (d) None

10. The transfer function is K/(S+1)(S+2)(S+3) the break point will lie between [ ]

(a) 0 and - (b) -1 and -2 (c) -2 and -3 (d) beyond -3

11. The system is represented by its transfer function has some poles lying on [ ]the imaginary axis, it is

(a) Unconditionally stable (b) Conditionally stable (c) Unstable (d) marginally stable12. The time that it takes to settle to the final value is called [ ]

(a)Steady state (b) transient state (c) both (d) None

13. When the gain K of a system is increased, the steady state error of the system [ ]

(a)Increase (b)remains unchanged (c)may increase or decrease (d) decrease

14. Classification of servo motor based on nature of supply [True/False]15. The static acceleration constant of a type 2 system is zero [True/False]16. The control systems are normally designed with damping factor less than unity [True/False]

17. Unit impulse function is derivative of _____________ function18. Parabolic function is called _____________________________19. The time that output takes to reach the steady state ______________________20. Laplace transform of unit ramp function ____________________


Class: III B.Tech .I-Sem. Branch: EEEI MID (Subjective)



NAME: ROLL NO:

Answer any three questions and each one carry equal marks


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1. What are the various types of control systems given an example of each? What are the advantages anddisadvantages of open loop and closed loop systems?

2. (a). Derive the transfer function of an AC servo meter and draw its characteristics(b). Explain the synchro error detector with circuit diagram

3. (a). Derive the expression for time domain specification of a standard second order system to astep input.

(b). Explain the generalized error coefficients and given relevant expressions to compute them.

4. The characteristic equation of a feedback control system is S^3+(K+0.5)S^2+5KS+50=0 using RH-criterion determined the value of K which the system is stable.

5. Convert the block diagram to signal flow graph and determined the transfer function using masonsgain formula.





NAME: ROLL NO:

Answer any three questions and each one carry equal marks

1. What are the various types of control systems given an example of each? What are the advantages anddisadvantages of open loop and closed loop systems?

2. (a). Derive the transfer function of an AC servo meter and draw its characteristics(b). Explain the synchro error detector with circuit diagram


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3. (a). Derive the expression for time domain specification of a standard second order system to astep input.


4. The characteristic equation of a feedback control system is S^3+(K+0.5)S^2+5KS+50=0 using RH-

criterion determined the value of K which the system is stable.

5. Convert the block diagram to signal flow graph and determined the transfer function using masonsgain formula.


Class: III B.Tech .I-Sem. Branch: EEEI MID (Objective)



NAME: ROLL NO:

ANSWER ALL THE QUESTIONS

1. The range of damping ratio for correlating time domain and frequency domain specifications is

______________________.

2. The slope of log magnitude curve near cut-off frequency is known as_____________.

3. The frequency at which the phase angle of the open-loop system is 180 deg. _______________

[phase crossover / Gain crossover] frequency.


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4. The reciprocal of magnitude of open loop system at phase crossover frequency is

_________________ [ ]

a) Phase margin b) Gain margin c) phase crossover frequency d) None

5. If W gc = W pc, the system becomes marginally stable. [True/ False]

6. The corner frequency for the factor 1/( S 2+ 20S+ 64) is [ ] a) 8 rad/sec b) 6 rad/sec c) 5 rad/sec d) 9 rad/sec

7. Type of the minimum phase system indicates the _______________(starting/ terminating) point

of the polar plot.

8. The circles in the polar plot indicates the ____________ ( magnitude/phase) of the system.

9. Polar plots are best suitable for marginally stable system. [True/False]

10. If a point is found to be inside the path, then the point is enclosed. [True/False]

11. Lag compensator improves the ______________ [steady state/ Transient] performance.

12. Lag compensator act as __________controller.13. Lag compensator improves the ______________ performance.

14. Lead compensation ____________[increases/ decreases] the Bandwidth.

15. Speed of response increases with the help of _________ compensation.

16. If n is the no. of state variables, r be the no. of i/p variables, then the order of the matrix B is

_________

17. State space model of an LTI system can be represented by the equations?

18. The matrix A for the given transfer function 10/ (s 3 +4s 2+2s +1)is

____________________

19. Transfer function model can be applicable to only linear systems. [True/ False]

20. Write the state equations for Homogenous LTI system _________________


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NAME: ROLL NO:

ANSWER ANY THREE QUESTIONS

1. a) State advantages & limitations of frequency domain analysis?b) Sketch the Bode plot for G(s) = 28.5e-0.1s / s(1+s)(1+0.1s) and find gain cross over

frequency?2. The open-loop transfer function of unity feedback control system is

G(s) = 10/s(s+1)(s+5). Draw its polar plot?3. Explain the design procedure of Lag compensator using Bode plot?

4. a) Obtain the state space model for the given transfer function

Y(S) / U(S) = 2/S3 +6s2+11S+ 6?

a) Explain the properties of state transition matrix?

5. Draw the Nyquist plot for the system whose transfer function is

G(s)H(s) = k/s(s+2)(s+10)?


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Question Bank

UNIT-I (DESCTRIPTIVE & OBJECTIVES)

1. What are the various types of control systems given an example of each? What are the advantagesand disadvantages of open loop and closed loop systems?

2 .Explain the significance of impulse response. Also explain the feedback characteristics and effect offeedback system.

3(a). Define transfer function also explain advantages and disadvantages of transfer function.

(b). Find the transfer function X 1(s)/F(s) for the system shown.

4. Write the differential equations governing the mechanical system shown in figure. Draw the force-voltage and force-current electrical analogous circuits and verify by writing mesh and node equations.


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UNIT-I BITS

1. The output of a feedback control system must be a function of [ d ](a)reference I/P & O/P (b)output (c)reference I/P (d) reference I/P& error signal

2. The transfer function of a system is the Laplace transform if its [ b ]

(a) ramp response (b) impulse (c) square wave (d) step

3. Any physical system which does not automatically correct for variation on it O/P [ b ]

is called

(a) unstable system (b) open loop system (c) closed loop system (d) None

4. Transfer function of a control system depends on [ d ]

(a) nature of output (b) nature of input

(c) initial conditions of I/P & O/P (d) system parameters only

5. Potentiometers are used in control system [ c ]

(a)to improve stability (b) to improve frequency response

(c) as error sensing transducer (d) to improve time response

6. In force-voltage analogy, mass equal in electrical system [ c ]


7. In force-voltage analogy, velocity equal in electrical system [ b ]

(a) voltage (b) current (c) inductance (d) resistance

8. In force-current analogy, dashpot equal in electrical system [ a ]

(a) voltage (b) capacitance (c)conductance (d) resistance

9. In force-current analogy, mass equal in electrical system [ c ]


10. Applied force equal to opposing forces. It is called ________ law [ b ]


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(a) Newtons first law (b) newtons second law (c) newtons third law (d)KVL

UNIT-II (DESCTRIPTIVE & OBJECTIVES)

1(a). With a neat sketch explain the construction and principle of working of the synchrotransmitter and receiver.

(b). Derive the transfer function for the synchro transmitter and receiver.

2(a). Derive the transfer function of an AC servo meter and draw its characteristics

(b). Explain the synchro error detector with circuit diagram

3. Convert the block diagram to signal flow graph and determined the transfer function usingmasons gain formula.

4. Using block diagram reduction technique find closed loop transfer function of the systemwhose block diagram is shown in figure.


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UNIT II BITS

1. The block diagram contains [ d ](a) System output variable (b) system input variable

(c)the functional relations of the variables (d) all of the above

2. The transfer function Eo(s)/E i(s) of the RC-network shown is given by [ a ]

(a) 1/(RCS+1) (b) 1/(RCS) (c) RCS/(RCS+1) (d) None3. In a signal flow graph, the nodes represents [ a ]

(a) The system variables(b) (b) the system gain(c) (c)the system parameters(d) (d)all of the above

4. The branch of a signal flow graph represents [ b ](a) The system variable (b) the functional relations of the variables (c) the system

parameters (d) none of the above5. By applying masons gain formula, it is possible to get [ c ]

(a) The ratio of output variable to input variable only(b) The system functional relations between any two variables(c) The overall gain of the system(d) The ratio of any variable to input variable only

6. Two or more loops in signal flow graph are said to be non touching [ d ](a) If they do not have any common loop(b) If they do not have any common branch(c) If they have common node(d) If they do not have any common node

7. Classification of servo motor based on [ a ](a) Nature of supply (b) output (c) response (d) none

8. AC servo motor is a [ b ](a)open loop CS (b) closed loop CS (c) mixed loop CS (d) None


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9. DC field controlled servo motor is a [ a ]

(a)open loop CS (b) closed loop CS (c) mixed loop CS (d) None

10. DC armature controlled servo motor is a [ b ]

(a)open loop CS (b) closed loop CS (c) mixed loop CS (d) None

UNIT-III (DESCTRIPTIVE & OBJECTIVES)

1(a). Derive the expression for time domain specification of a standard second order system to astep input.


2. A unity feedback system is characterized by the open loop transfer function

G(s)=1/(s(0.5s+1)(0.2s+1)) Determine the steady state errors for unit step, unit ramp and unitacceleration input. Also determined the damping ratio and natural frequency of the dominant roots.

3. The unity feedback system is characterized by an open loop transfer function G(s)= K/(s(s+10))

determined the gain K, so that the system will have a damping ratio of 0.5 for this value of K.Determined settling time and peak over shoot for a unit step input.

4. A position control system with velocity feedback is shown what is the response C(t) to the unitstep input given that =0.5also calculate rise time, peak time, maximum overshoot and settling time.

UNIT III BITS

1. The time that it takes to settle to the final value is called [ b ](a) Steady state (b) transient state (c) both (d) None

2. The time that output takes to reach the steady state [ a ](a) Steady state (b) transient state (c) both (d)none

3. Laplace transform of unit ramp function [ b ](a) 1/S (b) 1/S^2 (c) 1/S^3 (d) 1


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4. Parabolic function is called [ c ](a) Position function (b)velocity function (c)Acceleration function (d) None

5. Unit impulse function is derivative of _____________ function [ b ](a) Ramp (b) step (c) impulse (d) sine

6. The static acceleration constant of a type 2 system is [ d ](a) Infinite (b) zero (c) cannot be found out (d) finite

7. The time domain specification which is dependent only on the damping factor is [ d ](a) Rise time (b)peak time (c)settling time (d) peak overshoot

8. When the gain K of a system is increased, the steady state error of the system [ d ](a) Increase (b)remains unchanged (c)may increase or decrease (d) decrease

9. The static error constants depends on [ b ](a) The order of the system (b) the type of the system(c)Both type and order of the system (d) None

10. The control systems are normally designed with damping factor [ c ](a) More than unity (b) of zero (c) less than unity (d) of unity

UNIT-IV (DESCTRIPTIVE & OBJECTIVES)

1. Sketch the root locus of the system whose open loop transfer function is G(s)=K/(S(S+2)(S+4)) find the value of K so that the damping ratio of the closed loop systemis 0.5

2. Sketch the root locus for the unity feedback system whose open loop transfer function isG(s)H(s)= K/((S(S+4)(S^2+4S+20))

3(a). The characteristic equation of a feedback control system is S^3+(K+0.5)S^2+5KS+50=0using RH-criterion determined the value of K which the system is stable.

(b) Determine (i) the number of root loci (ii) number of asymptotes

(c) root loci on the real axis if any for the following : G(s)H(s)= K(S+1)/((S^3(S+2)(S+3))

4. Construct routh array and determine the stability of the system represented by thecharacteristic equation S^5+S^4+2S^3+3S+5=0 comment on the location of the roots of thecharacteristic equation.

UNIT IV BITS


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1. Consider characteristic s equation S^4+3S^3+5S^2+6S+K+10=0 condition [ ]for stability is(a) K>5 (b) - 10K (c) K> -4 (d) -10


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Previous years question papers JNTUA

AnsweranyFIVEquestions

Allquestionscarryequal

marks***

**

1 (a) Explain theclassificationofcontrol systemswithexamples.(b) Find thetransferfunction for thefollowingsystem showninfigure1.

J1J2

T K(AppliedTorque)

(output) B

Figure12 (a) Drawtheconnectiondiagram ofSynchropair usedasapositionindicator.

(b) Drawthesignalflowgraphfor thesystemofequationsgivenbelowandobtaintheoverall transferfunctionusingMason s rule:X2=X1 X6 X3=G 1X2-H2X4-H3X5 X4=G 2X3-H4G 6 X5=G 5X4


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X6=G 4X5

3 (a) Derive thestaticerrorconstantsand list thedisadvantages.(b) Aunitfeedbacksystemischaracterizedbyanopen-looptransferfunctionG(s)= .

DeterminethegainKsothatthesystemwillhaveadampingratioof0.5. Forthisvalue

ofKdeterminesettlingtime,peakovershootand times topeakovershoot foraunit-step input.

4 (a)(b)

Howthe rootsof thecharacteristicequationarerelated tostability?The open loop transfer function of negative unity feedback system is given by G(s)= .SketchtherootlocusforK>0. DeterminetherangeofKforwhich thesystemisstable. AlsofindthevalueofKforwhichthesystemoscillatesand frequencyofoscillation.

5 (a)(b)

Explain thecorrelationbetween timeandfrequency responseofasystem.Explain thefrequency responsespecifications.

6 (a)(b)

Draw&explainpolarplotsfor type 0, type -1&type 2systems.Writeanoteonrelationbetween rootloci&Nyquistplots.

Contd.in Page2

Page

10f2


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Code:9A19401 1

7 AunityfeedbacksystemhasanopenlooptransferfunctionG(s)= . Designasuitablelogcompensatorsothatphasemarginis40 0andthesteadyerrorforrampinputislessthanor equalto0.2.

8 (a) Considerthenetworkshowninfigure2andobtain thestatevariableform: A

iL L

iC R i VC Vo

C

Figure2(b) Explainpropertiesandsignificanceofstate transition matrix.

*****

Page20f2


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Code:9A19401 2 II B.TechII Semester (R09)Regular Examinations,April/May2012

CONTROLSYSTEMS (Electronics &Computer Engineering)

Time:3hours MaxMarks:70

AnsweranyFIVEquestions All questionscarryequal marks

*****

1 (a) Explain thedifferencebetweenopenloopandclosedloopsystems. (b) Derive thetransfer functionfor thefollowingrotational mechanical systemsshowninfigure1

Disc

K

ShaftB

StiffnessK

TViscousfluid

RotationalFigure1

2 (a) Explain theneedofMason s gainformulafor anysystem reduction.(b) Obtainthe transfer functionof oftheelectrical networkshowninfigure2

R1 R 2

e i L C e o c1 c2

figure2

3 (a) Explainerror constantsK p,Kv,Kafor type -1system.(b) TheopenlooptransferofaunityfeedbackcontrolsystemisgivenbyG(s)= where

KandTarepositiveconstants. Bywhat factor should theamplifier gainbe reducedsothatthepeakovershoot ofunitstepof thesystemisreducedfrom 75%to25%.

Contd.inpage2

Page1of2


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Code:9A19401 2

4 (a) A unity feedback control system is characterized by the open-loop transfer functionG (s)= .

(i) UsingtheRouth scriterion,determinetherangeofvaluesofKforthesystemtobe

stable.(ii) Checkif forK= 1, all therootsof thecharacteristicequationof theabovesystemhavedampingfactor greater than0.5.

(b) Calculate the values of K and for the point in S-plane at which the root locus ofG(s)H(s)= intersectstheimaginaryaxis.

5 DrawthebodeplotsandfindthegainmarginandphasemarginofasystemrepresentedbyG(s)H(s) =

6 What isNyquistpath?PlotNyquiststabilityforG(s)H(s) =

7 FortheunityfeedbackcontrolsystemforwardpathtransferfunctionG(s)= . Designa

lag-leadcompensatorsothatPM 40 0 andsteadystateerrorforunitramp input 0.04rad.

8 (a) Definestate, statevariableandexplain thesignificanceofstatevariableanalysis. (b) Asystem isdescribedby:

u.

Find thetransferfunctionandconstruct thesignalflowgraph.

*****

Page2of2


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Code:9A19401 3

5 (a) Showthatinbodemagnitudeplottheslopecorrespondingtoaquadraticfactoris-40 dB/dec.

(b) Explainwith thehelpofexamples: (i) Minimumphasefunction

II B.TechII Semester (R09)Regular Examinations,April/May2012CONTROLSYSTEMS

(Electronics &Computer Engineering)Time:3hours MaxMarks:70


*****

1 (a) What isfeedback?Explain theeffectof feedbackonstability.(b) Obtainthe transfer functions and ofthemechanical system showninfigure1

4 x 1 x2

K1 K3 K2

m1 m 2

b1 b2

Figure1

2 (a) Explain thedifferencesbetweenAC servomotorandDC servomotor. (b) Determinethe transfer functionC(s)/ R(s) for thefollowingblockdiagram (figure2)

R + C

G1 G2 +

+ -G3 H1

Figure2

3 (a) Definetimeconstant andexplainitsimportance. (b) Foranegativefeedbackcontrolsystem having forwardpathtransferfunction:

G(s)= andH(s)=1,determinethevalueofgainKforthesystemtohavedamping

ratio of 0.8. For this value of gain K, determine the complete time responsespecifications.

4 (a) Definetheterms:(i)Absolutestability (ii)Marginal stability (iii)Conditional stability. (b)Plottherootlocifor theclosedloopcontrol systemwithG(s) = H(s)= 1.

(ii)Nonminimum phasefunction (iii)All pass function.

Page1of2Contd.in Page2


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Code:9A19401 3

6 (a) ExplainNyquiststabilitycriterion. (b) Aunityfeedbackcontrolsystemhasanopenloop transfer functiongivenby

G(s)H(s)= . Drawthe Nyquistdiagramanddetermineitsstability.

7 For G(S) = . Designalagcompensator givenphasemargin 35 0andK v 20.

8 Writethestateequationsofthesystemshowninfigure3inwhichX 1,X2andX 3constitutethestatevector. Determinewhetherthesystem iscompletelycontrollableandobservable.

U(s) +

+

+ -

X3(s)

x1(s)


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S

Figure3

**Code:9A19401

II B.TechIISemester(R09)RegularExaminations,April/May 2012 CONTROL SYSTEMS

(Electronics&Computer Engineering)

Time:3hours MaxMarks:70

AnsweranyFIVE questions

Allquestionscarryequal marks

1 (a) Explainwithexample,theuseof controlsystemconceptstoengineeringandnonengineeringfields. (b) Forthemechanicalsystemfigure1given,writedownthedifferentialequationsofmotionandhence

determineth e . F(t)Y2

K1 K2B2

M1M2

B1 1

2 (a)(b)

Derivethetransferfunctionforthefieldcontrolledd.c.servomotorwithneatsketch.Explaintheadvantagesandfeaturesof transferfunction.

3 (a)(b)

Derivethetimeresponseof secondorderunderdampedsystemduetounitstepinput. Theunitstepresponseofasecondorderlinearsystemwithzeroinitialstateisgiven by c(t)=1+1.25 e -6t (sin8t-tan -11.333). Determinethedampingratio,undampednaturalfrequencyofoscillationsandpeak overshoot.

4 (a) ShowthattheRouth sstabilitycriterionandHurwitzstabilitycriterionareequivalent. (b) Drawtheroot locusdiagramforafeedbacksystemwithopen-looptransferfunction

G(s)= followingsystematicallythe rulesforthe constructionofroot locus. Showthattherootlocus inthecomplexplaneis acircle.

5 (a) Definebandwidthandderivetheexpressionforthebandwidthof asecondordersystem. (b) Bring out the correlation between time response &frequencyresponse and hence show that the

correlationexistsfortherangeof dampingration0


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7 TheuncompensatedopenlooptransferfunctionofaunityfeedbacksystemisG(s)= . Designa phase-leadcompensatortomeetthespecifications:(i)Foraunitramp-inputthe steadystateerrorshould

belessthanorequalto 0.1units.(ii)Phasemarginof thesystembegreaterthan400

. 8 (a) Definecontrollabilityandobservability.

(b) Considernowthatthesystemhasforcingfunctionandisrepresentedbythefollowingnonhomogeneous stateequation whereu is thestepfunction. Computethesolutionof this

equationassumingtheinitialstatevectoris x 0= .

ELECTRICAL AND ELECTRONICS MEASUREMENT

Syllabus

JAWAHARLAL NEHRU

TECHNOLOGICAL UNIVERSITY ANANTAPUR



32/160

4 0 4

(9A02501) ELECTRICAL & ELECTRONIC MEASUREMENTS

Objective :Electrical measurements course introduces the basic principles of all measuring instruments. It also deals with themeasurement of RLC parameters voltage, current Power factor, power, energy and magnetic measurements andDigital Meters UNIT-I MEASURING INSTRUMENTS Classification deflecting, control and damping torques Ammeters and Voltmeters PMMC, Dynamometer,moving iron type instruments expression for the deflecting torque and control torque Errors and compensations,extension of range using shunts and series resistance.

UNIT II INSTRUMENT TRANSFORMERS AND P.F METERCT and PT Ratio and phase angle errors design considerations. Types of P.F. Meters dynamometer and moving

iron type 1-ph and 3-ph meters.

UNIT III MEASUREMENT OF POWER / ENERGYSingle phase dynamometer wattmeter, LPF and UPF, Double element and three element dynamometer wattmeter,expression for deflecting and control torques. Single phase induction type energy meter driving and brakingtorques errors and compensations. Three phase energy meter.

UNIT I V POTENTIOMETERSPrinciple and operation of D.C. Cromptons potentiometer standardization Measurement of unknown resistance,current, voltage.

A.C. Potentiometers: polar and coordinate types standardization applications.

UNIT V D.C & A.C BRIDGESMethod of measuring low, medium and high resistance sensitivity of Wheatstones bridge Kelvins double bridgefor measuring low resistance, measurement of high resistance loss of charge method. Measurement of inductance- Maxwells bridge, Andersons bridge. Measurement of capacitance and loss angle - Desauty bridge. Wiens bridge Schering Bridge.

UNIT VI MAGNETIC MEASUREMENTSBallistic galvanometer equation of motion flux meter constructional details, comparison with ballisticgalvanometer. Determination of B-H Loop methods of reversals - six point method A.C. testing Iron loss of barsamples.

UNIT VII OSCILLOSCOPECathode Ray Oscilloscope- Cathode Ray tube-Time base generator-Horizontal and Vertical amplifiers application ofCRO Measurement of phase , frequency, current & voltage- Lissajous pattern

UNIT VIII DIGITAL METERSDigital Voltmeter-Successive approximation, ramp and integrating type-Digital frequency meter-Digital multimeter-Digital Tachometer

TEXT BOOK:1. Electrical Measurements and measuring Instruments by E.W. Golding and F.C. Widdis, 5 th Edition, Reem

Publications.2. Electrical & Electronic Measurement & Instruments by A.K.Sawhney Dhanpat Rai & Co. Publications.


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3. Electrical & Electronic Measurement & Instrumentation by R. K. Rajput, 2 nd Edition, S. Chand & Co.4. Electronic Instrumentation by H. S. Kalsi, Tata Grawhill Mc, 3 rd Edition.REFERENCE BOOKS:

1. Electrical Measurements by Buckingham and Price, Prentice Hall2. Electrical Measurements: Fundamentals, Concepts, Applications by Reissland, M.U, New Age International (P)

Limited, Publishers.


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Objective

IMPORTANCE OF THE ELECTRICAL AND ELECTRONICS MERASUREMENTS

Electrical measurements course introduces the basic principles of all measuring instruments. It alsodeals with the measurements of RLC parameters, voltage, current, power, power factor , energy andmagnetic measurements and digital meters.


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The first unit comprises of the various measuring instruments to measure our basic electricalquantities I.e, DC voltage and DC current by PMMC instruments, AC voltage and AC current by using MIinstruments and AC power by using Electro Dynamometer type instruments.

In second unit we will discuss about CT and PT which are used to step down the voltages andcurrents in our transmission lines respectively for relay operation. We also discThe single phase and threephase power factor of the load by using single phase and three phase power factor meters.

In third unit we will discuss how we can measure power . Basically we have DC power and ACpower. To measure DC power we have V-A method and A-V method. To measure Ac power we havewattmeter methods. By watt meters we can measure single phase power and three phase power. In thethird unit we will discuss about the energy meters also.By using this energy meters we can know the tariffof our homes.

In this measurements subject in the remaining units we will know about how we can

measure resistance by using DC bridges and how we can measure L & C by using AC bridges.We also knowabout the Electronic Measurements In last two units.


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Lesson Plan

PBR VISVODAYA INSTITUTE OF TECHNOLOGY AND SCIENCE::KAVALI

LESSON PLAN Department of EEE

Academic Year: 2012 2013 CLASS: III YEAR- I SEM

Faculty Name: G.SUMAN Subject: Electrical Measurements


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S.No Dates

No. ofperiods

In week Topic to be covered

No. ofPeriods

Required

Total

Periods

Per unit

15

UNIT -I : measuring instruments Classification

deflecting, control and damping torques-

ammeters and voltmeters-PMMC, moving iron type

instruments expression for deflecting torque

1

2

2

11

24

Moving iron type instruments expression for

deflecting torque and Control torque errors and

compensations, extension of range using shunts and

series resistance.

2

1

1

3

5

ynamometer type instruments-torque equations

Errors and extension of range

1

1

UNIT II: instrument transformer

CT and ratio and phase angle errors

Design Considerations.

1

2

8

45

PT ratio and phase angle errors design

Considerations.

Type of P.F meters- dynamometer and

moving iron type-1-ph and 3-ph mete

1

2

2

55

UNIT III: measurement of power

Single phase dynamometer wattmeter , LPF and UPF,

double element and three element dynamometer

wattmeter. expression for deflecting and control torques

2

2

1

86

3Single phase induction type energy meter driving

2

1


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and braking torques-errors and compensations.

three phase energy meter.

75

UNIT-IV: potentiometers: Principle and operation

of d.c Cromptons potentiometer standardization

measurement of unknown Resistance ,current ,voltage

1

2

2

84

A.C. potentiometers : polar type and

coordinate types

standardization

applications

1

2

1 9

9 5

Revision for I Mid Exams

5 5

I MID EXAMINATIONS (03-09-2012 to 05-09-2012)

10

2

UNIT-V: D.C and A.C Bridges:

Method of measuring low, medium and high resistance-

Sensitivity of WHEATSTONES bridge - KELVINS

double bridge-for measuring low resistanceeasurement

of high Resistance

2

711

5

loss of charge method.

Measurement of inductance- Maxwells bridge,

Andersons bridge.

Measurement of capacitance and loss angle

DesautyBridge. Wiens bridge - Schering bridge.

1

1

1

2


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12 5

UNIT-VII : magnetic measurements:

Ballistic galvanometer equation of motion

Flux meter-constructional details, comparison with

Ballistic galvanometer. determination of b-h loop

methods reversals

1

2

2

813

5

six point method A.C testing iron losses of

bar samples

2

1

Unit VII: Oscilloscope: Cathode Ray Oscilloscope

Cathode ray tube11

14 4

Time base generators-

horizontal and vertical amplifiers

applications of frequency- measurement of phase

Frequency, current and voltage.

1

2

1

8

15 5

lissajous pattern

UNIT-VIII:Digital meters

Digital voltmeter-Successive approximation

Ramp type digital frequency meter

2

1

2

816 5 integrating type digital frequency meter

Digital multimeter

Digital Tachometer

1

2

2

4

Revision for II Mid Exams

4


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17 4

Total Available 76 Total Required 76

Signature of the staff-in charge Signature of the HOD


41/160

Question Papers Mid-semester examinations

PBR VI SVODAYA INSTI TUTE OF TECHN OLGY AND SCIENCE :: KA VAL I (Approved by A.I.C.T.E- New Delhi, Affiliated to J.N.T. University, Anantapur) Janata peta, Kavali,

S.P.S.R Nellore (Dist), A. PSubject Name: EEM I st MID-Descriptive test Year & Branch: III B.Tech -I SemEEE

Answer any three questions.each one carries 10 marks. 10X3=30

1.a) explain the working of a universal shunt used for multi range ammeter?b)write the significance of control anddamping torque?

2.)explain the working of attraction type moving iron instruments. List the advantages and disadvantages of the

moving iron instruments?

3.)With a neat diagram ,explain the working of dynamometer type power factor meter?

4.)Show that Tan= .if and are the readings of two watt meters used in two wattmeter method ?

5.)explain the measurement of unknown emf using dc cromptons potentiometer?

VISVODAYA ENGINEERING COLLEGE :: KAVALI (Approved by A.I.C.T.E- New Delhi, Affiliated to J.N.T. University, Anantapur) Janata peta, Kavali, S.P.S.R Nellore

(Dist), A. PSubject Name: EEM I st MID-Descriptive test Year & Branch: III B.Tech -I SemEEE

Answer any three questions.each one carries 10 marks. 10X3=30

1.a) explain the working of a universal shunt used for multi range ammeter?b)write the significance of control anddamping torque?


42/160

2.)explain the working of attraction type moving iron instruments. List the advantages and disadvantages of themoving iron instruments?

3.)With a neat diagram ,explain the working of dynamometer type power factor meter?

4.)Show that Tan= .if and are the readings of two watt meters used in two wattmeter method ?

5.)explain the measurement of unknown emf using dc crompto ns potentiometer?

PBR VI SVODAYA INSTITUTE OF TE CHNOLGY AND SCIENCE :: K AVAL I(Approved by A.I.C.T.E- New Delhi, Affiliated to J.N.T. University, Anantapur) Janata peta,Kavali, S.P.S.R Nellore (Dist), A.P.

Subject Name: EEM I st MID-Objective test Year & Branch: III B.Tech -I Sem EEE

Name: Roll No: Max Marks:10M

1.)The high torque to weight ratio in an analog indicating instrument indicates [ ] a)high friction loss b)low friction lossess c)hysteresis loses d)frequency losses

2.) The scale of the moving iron instrument is [ ]a)uniform b)Non-uniform c)neither uniform nor non uniform3.)In gravity control system [ ]

a) I cos b) I sin c)I d) I tan 4.)The controlling torque in 1- power factor meter is provided by [ ]a)spring control b)gravity control c)stiffness of suspension d)none of the above

5.)The transformers use in conjunction with measuring instruments for measurement purpose [ ]

is calleda)C.T. b)P.T. c)Power transformers d)Instrumental transformers6.)The deflection of the power factor meter is [ ] a) b)cos

c)sin d)none7.)In rotating field type power factor meter we have [ ] a)3 fixedcoils b)one fixe coils c)two fixed coils8)In rotating field type moving iron power factor meter the field of the fixed coil is [ ]a)alternating field b)rotating field c)constant field9.)The moving coil in a dynamometer wattmeter is connected [ ] a)In serieswith the fixed coil b)across the supply c)In series with the load d.)across the load10.)A potentiometer is basically a [ ]a)Deflecting type instruments b)null type instrument c)digital instrument d)None

11.)in moving coil instruments the deflection is directly proportional to 12.)By using potentiometers we canmeasure 13.)A dc potentiometer is designed to measureup to 2V with a slide wire of 800mm.A standard cell emf 1.18V .obtains balance at 600cm.A test cell is seen toobtain balance at 680mm.The emf of test cell is14.)A dynamometer type watt meter responds to the value of active power. 15.)A dc ammeter has aresistance of 0.1 and its current range is (0 -100A).If the range is to be extended to (0-500A), then shuntresistance is . 16.)The power of a 3-,3-wire balanced systemwas measured by two wattmeter method. The reading of One of wattmeter was found to be double that of theother. What is the power factor of the system

.


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17.)The minimum NO. of wattmeters required to measure 3-,3-wire balanced or unbalanced power is18.)The power expression in 3- circuit in terms of line voltage ,line current and power factor of the load is

.Where is the angle between voltage and current. 19.) The scale of the moving ironinstrument is 20) The minimum NO. of wattmeters required to measure 3-,4-wire unbalanced power is

VISVODAYA ENGINEERING COLL EGE :: KAVALI (Approved by A.I.C.T.E- New Delhi, Affiliated to J.N.T. University, Anantapur) Janata peta, Kavali, S.P.S.R Nellore (Dist),A. P

Subject Name: EEM I st MID-Objective test Year & Branch: III B.Tech -I Sem EEE Name: Roll No: Max Marks:10M

1.)The high torque to weight ratio in an analog indicating instrument indicates [ ]

a)high friction loss b)low friction lossess c)hysteresis loses d)frequency losses2.) The scale of the moving iron instrument is [ ]a)uniform b)Non-uniform c)neither uniform nor non uniform3.)In gravity control system [ ]

a) I cos b) I sin c)I d) I tan 4.)The controlling torque in 1- power factor meter is provided by [ ]a)spring control b)gravity control c)stiffness of suspension d)none of the above

5.)The transformers use in conjunction with measuring instruments for measurement purpose [ ]is calleda)C.T. b)P.T. c)Power transformers d)Instrumental transformers

6.)The deflection of the power factor meter is [ ] a) b)cos

c)sin d)none7.)In rotating field type power factor meter we have [ ] a)3 fixedcoils b)one fixe coils c)two fixed coils8)In rotating field type moving iron power factor meter the field of the fixed coil is [ ]a)alternating field b)rotating field c)constant field9.)The moving coil in a dynamometer wattmeter is connected [ ] a)In serieswith the fixed coil b)across the supply c)In series with the load d.)across the load10.)A potentiometer is basically a [ ]a)Deflecting type instruments b)null type instrument c)digital instrument d)None

11.)in moving coil instruments the deflection is directly proportional to12.)By using potentiometers we canmeasure 13.)A dc potentiometer is designed to measureup to 2V with a slide wire of 800mm.A standard cell emf 1.18V .obtains balance at 600cm.A test cell is seen toobtain balance at 680mm.The emf of test cell is14.)A dynamometer type watt meter responds to the value of active power. 15.)A dc ammeter has aresistance of 0.1 and its current range is (0 -100A).If the range is to be extended to (0-500A), then shuntresistance is . 16.)The power of a 3-,3-wire balanced systemwas measured by two wattmeter method. The reading of One of wattmeter was found to be double that of theother. What is the power factor of the system

.17.)The minimum NO. of wattmeters required to measure 3-,3-wire balanced or unbalanced power is18.)The power expression in 3- circuit in terms of line voltage ,line current and power factor of the load is

.Where is the angle between voltage and current. 19.) The scale of the moving iron


44/160

instrument is 20) The minimum NO. of wattmeters required to measure 3-,4-wire unbalanced power is

PBR VISVODAYAYA INSTITUTE OF TECHNOLGY AND SCIENCE::KAVALI

III.B.TECH,I-SEM,II MID EXAMINATION,November-2012

Branch: EEE

Time:1:30 Mins Subject: EEM(Descriptive)

**Answer any three questions. Each one carries equal marks. 3X10=30

1.(a)Draw the circuit of a Kelvins double bridge used for measurement of low resistances .Derive the

conditions for balance.

(b)A 4terminal resistor approximately of 50 resistances was measured by means of Kelvin double bridge having

the following component resistances:

standard resistor=100.02

Inner ratio arms=100.30 and 200

Outer ratio arms=100.23 and 200

Resistance of link connecting the standard and the unknown resistance is 700 . Find unknown

resistance

2.(a ).Derive the equation of balance for an Andersons bridge .Draw the phasor diagram for conditions under

balance. Discuss the advantages and disadvantages of this bridge.

(b)Write the CRO applications

3.(a) How the phase and frequency can be measured with the use of a CRO. Explain?

(b)Explain the functions of the following controls:

i). intensity ii). Focus

iii). Horizontal and vertical positioning iv). synchronization


45/160

4.) Explain the method of measuring voltage in successive approximation method.

5.(a)Explain the determination of B-H loop method of reversals.

(b)Discuss the constructional details of Ballistic galvanometer?

*THERE IS NO SUBSTITUTE FOR HARDWORK*

VISVODAYA ENGINEERING COLLEGE :: KAVALI


Branch: EEE

Time:1:30 Mins Subject: EEM(Descriptive)

**Answer any three questions. Each one carries equal marks. 3X10=30

1.(a)Draw the circuit of a Kelvins double bridge used for measurement of low resistances.Derive the

conditions for balance.

(b)A 4terminal resistor approximately of 50 resistances was measured by means of Kelvin double bridge having

the following component resistances:

standard resistor=100.02

Inner ratio arms=100.30 and 200


46/160

Outer ratio arms=100.23 and 200

Resistance of link connecting the standard and the unknown resistance to the nearest 0.01.

2.(a).Derive the equation of balance for an Andersons bridge.Draw the phasor diagram for conditions under

balance.Discuss the advantages and disadvantages of this bridge.

(b)Write the CRO applications

3.(a) How the phase and frequency can be measured with the use of a CRO.Explain?

(b)Explain the functions of the following controls:


iii). Horizontal and vertical positioning iv). synchronization

4.) Explain the method of measuring voltage in successive approximation method.

5.(a)Explain the determination of B-H loop method of reversals.

(b)Discuss the constructional details of Ballistic galvanometer?

*THERE IS NO SUBSTITUTE FOR HARDWORK*

PBR VISVODAYAYA INSTITUTE OF TECHNOLGY AND SCIENCE::KAVALI



47/160

Branch: EEE

Time:20 Mins Subject: EEM(Objective)

NAME: ROLL NO:

1. )The common bridge for precise measurement of inductance over a wide range is [ ]a)Maxwells bridge b)Hay s bridge c)Anderson bridge d)None

2.)The bridge most commonly employedfor measurement of frequency is [ ]

a)Owens bridge b)Hay s bridge c)schering bridge d)Weins bridge

3.)A multimeter is used to measure [ ]

a)resistance b)Voltage c)Current d)all of the above

4.)Which one of the following is measured by the loss of charge method [ ]

a)Low R b)High R c)Low L d)High L

5.) A dc voltage of 1V is applied to the X-plates of a CRO and ac voltage 2sin100t is applied to the Y-plates .Theresulting display on the CRO screen will be [ ]

a)vertical stright line b)horizontal stright line c)sine wave d)slant line

6)While measuring the phase difference between the V 1(t)=10sinwt and V 2(t)=10sin(wt +),the Lissajous patternobserved on CRO was a circle. The value of is [ ]

a)zero b)/4 c)/2 d)

7.) A certain oscilloscope with 4cmX4cm screen has its own sweep output fed to its input.If the X and Ysensitives are same ,the oscilloscope will display a [ ]

a)sawtooth b)triangular c)diagonal line d)horizontal line

8.)The X and Y inputs to a CRO are respectively 10cos(wt +) and 10sin(wt +) . The resulting Lissajous pattern is [ ]

a)Stright line b)Horizontal line c)ellipse d)Circle

9.)Voltages V y=100sin100t and V x=50sin100t are connected to Y and X terminals of a CRO respectively. What is theshape of the screen on the CRO [ ]

a)Circle b)straight line c)An ellipse d)A parabola

10.) Paramanent magnets are tested by [ ]


48/160

a)ballistic methods b)using an electric circuit having mutual inductance

c)potentiometer method d)None

11.)The approximate input impedance of the CRO [ ]

a)1MHz b)10MHz c)100MHz d)20MHz

12.)The construction of Fluxmeter is similar to ____________milli ammeter [ ]

a)MC b)MI c)Dynamometer type d)electrostatic

13.)High resistances are in the range of

a)99.9K b)1M c)>100K d)None

14.)The meter used to measure resistance is____________________.

15.)Medium resistances are from _____to________.

16.)The continuity in underground cables can be detected by using_______________.

17.) The flux meter have__________ damping torque __________ control torque.

18.) If hysteresis loop of a particular material is widen then the permittivity of the material is

_______________.

VISVODAYAYA ENGINEERING COLLEGE::KAVALI


Branch: EEE

Time:20 Mins Subject: EEM(Objective)

NAME: ROLL NO:

1. )The common bridge for precise measurement of inductance over a wide range is [ ]a)Maxwells bridge b)Hay s bridge c)Anderson bridge d)None

2.)The bridge most commonly employedfor measurement of frequency is [ ]

a)Owens bridge b)Hay s bridge c)schering bridge d)Weins bridge


49/160



4.)Which one of the following is measured by the loss of charge method [ ]


5.) A dc voltage of 1V is applied to the X-plates of a CRO and ac voltage 2sin100t is applied to the Y-plates .Theresulting display on the CRO screen will be [ ]


6)While measuring the phase difference between the V 1(t)=10sinwt and V 2(t)=10sin(wt +),the Lissajous patternobserved on CRO was a circle. The value of is [ ]

a)zero b)/4 c)/2 d)

7.) A certain oscilloscope with 4cmX4cm screen has its own sweep output fed to its input.If the X and Ysensitives are same ,the oscilloscope will display a [ ]

a)sawtooth b)triangular c)diagonal line d)horizontal line

8.)The X and Y inputs to a CRO are respectively 10cos(wt +) and 10sin(wt +) . The resulting Lissajous pattern is [ ]


9.)Voltages V y=100sin100t and V x=50sin100t are connected to Y and X terminals of a CRO respectively. What is theshape of the screen on the CRO [ ]

a)Circle b)straight line c)An ellipse d)A parabola

10.) Paramanent magnets are tested by [ ]





12.)The construction of Fluxmeter is similar to ____________milli ammeter [ ]


13.)High resistances are in the range of



50/160



16.)The continuity in underground cables can be detected by using_______________.

17.) The flux meter have__________ damping torque __________ control torque.

18.) If hysteresis loop of a particular material is widen then the permittivity of the material is

_______________.


51/160

Question Bank


52/160

ELECTRICAL ELECTRONICS MEASUREMENTS

UNIT-1

1.a) explain the working of a universal shunt used for multi range ammeter?

1.b)write the significance of control and damping torque?

2)explain the construction and working of PMMC instrument and also derive thetorque equation for that?

3.)with a neat diagram explain the working of dynamometer type instrument?

4.)explain the working of attraction type moving iron instruments. List theadvantages and disadvantages of

the moving iron instruments ?

BITS

1.) The high torque to weight ratio in an analog indicating instrument indicates [ b]

a)high friction loss b)low friction losses

c)hysteresis losses c)frequency losses

2.) Horizontally placed instruments are used[ a ]

a)spring control system b)gravity control system

c)both c)none

3.) Which meterial is used for shunts of dc instrument[ a ]

a) manganin b)constantan

c)copper d)silver


53/160

4.)In moving iron instruments the deflection is directly proportionalto[ c ]

a) I b)I/2 c) d)

5)A 100A ammeter has an internal resistance of 100 .For extending its range tomeasure 500A,the

shunt required is

a) 20 b)22.22 c)25 d)50 [C]

6.)in moving coil instruments the deflection is directly proportional to

[ a ]

a) I b)I/2 c) d)

7.) The scale of the moving iron instrument is[ b ]

a)uniform b)Non-uniform

c)neither uniform nor non uniform

8)An ammeter with input resistance of 50 gives full scale deflection for 50Acurrent.The input resistance of (0-1mA) ammeter obtained by connecting a shuntacross the (0-50A)meter will be[d]

a)50 b)25 c)5 d)2.5

9.)A dc amme ter has a resistance of 0.1 and its current range is (0 -100A).If therange is to be extended to

(0-500A), then shunt resistance is

[ c ]a)0.010 b)0.011 c)0.025 d)1.0

10.)In gravity control system[ b ]

a)I cos b)I sin c)I d) I tan


54/160



55/160

UNIT 2

1.)Discuss C.T. and P.T. Define ratios of instrument transformers?

2.)Explain the advantages and disadvantages of instrument transformers?

3.)With a neat diagram ,explain the working of dynamometer type power factor

meter?4.)With a neat diagram ,explain the working of rotating field type moving iron

power factor meter?

BITS

1.)The controlling torque in 1- power factor meter is provided by[ d ]

a)spring control b)gravity control

c)stiffness of suspension d)none of the above

2.)The transformers use in conjunction with measuring instruments formeasurement purpose

is called

a)Current transformer b)Potential transformer [ d ]

c)Power transformers d)Instrumental transformers

3.)The transformer used for measurement of current is called [a]

a)Current transformer b)Potential transformer


56/160


4.)The transformer used for measurement of voltage is called [b]

a)Current transformer b)Potential transformer


5.)The current in the primary winding of a current transformer depends upon[ b ]

a)burden of the secondary winding of transformer

b)load connected to the system in which C.T. is installed

c)both buren of the transformer secondary winding and load connected to thesystem

d)none of the above

6.)The burden of the current transformer is expressed in terms of the [ b]

a)secondary winding current b)VA rating of the transformer

c)voltage,current and power factor of the system

d)None of the above

7.)The deflection of the powerfactor meter is

[ a ]a) b)cos c)sin d)none

8.)In current transformer ,the error in phase angle and transformation ratiois mainly

due to [ a ]

a)Ie,Im, b)n, Is, c)n,Is, d)none


57/160

9.)In rotating field type power factor meter we have[ a]

a)3 fixed coils b)one fixe coils c)two fixed coils d)none

10)In rotating field type moving iron power factor meter the field of the fixed coil is [ b ]

a)alternating field b)rotating field c)constant field d)none


UNIT -3

1.)Discuss the errors and compensations of singlephase energy meter?

2.)With a neat sketch explain the working of 1- electro dynamometer wattmeter?

3.)What is the significance of driving torque and breaking torquesin 1- inductiontype energy meter?


58/160

4.)Show that Tan = .if and are the readings of two watt meters used

in two wattmeter method ?BITS

1.)Which one of the following defect is responsible for creeping in an induction typeenergy meter [ b ]

a)imperfect lag compensation b)over friction compensation

c)imperfect overload compensation

2.)The power of a 3-,3-wire balanced system was measured by two wattmetermethod. The reading of

One of wattmeter was found to be double that of the other. What is the powerfactor of the system [ d ]

a)1 b)0.866 c)0.707 d)0.5

3.)The voltage coil of a single phase house service energy meter

[ b ]

a)Highly resistive b)highly inductive c)highly inductive

4.)The moving coil in a dynamometer wattmeter is connected[ b ]

a)In series with the fixed coil b)across the supply

c)In series with the load d.)across the load

5.)A dynamometer type watt meter responds to the[ a ]

a)Average value of the active power b)Average value of the reactive power

c)Peak value of the reactive power d)Peak value of the active power

6.)The minimum number of wattmeters required to measure 3-,3-wire balanced orunbalanced power [ b ]


59/160

a)1 b)2 c)3 d)4

7.)Which of the following condition must be satisfied for the two wattmeter methodof 3- power

measurement [ c ]

a)Load must be balanced b)source must be balanced

c)system should be 3-,3-wire type d)none

8.) The minimum number of wattmeters required to measure 3-,4-wire balancedpower is [ a ]

a)1 b)2 c)3 d)4

9) The minimum number of wattmeters required to measure 3-,4-wire unbalancedpower is [ c ]

a)1 b)2 c)3 d)4

10.)The power expression in 3- circuit in terms of line voltage ,line current andpower factor of the

load is .Where is the angle between[ c ]

a)Line voltage and line current b)Line voltage and phase current

c)Phase voltage and line current d)Phase current and phase voltage


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UNIT-4

1.)explain the measurement of unknown emf using dc crompton,s potentiometer?

2.)Explain the applications of dc potentiometers?3.)Explain about standardization of dc potentiometer?

4.)With a neat diagram explain the working of polar type AC potentiometer?

BITS

1.)A potentiometer is basically a[ b ]

a)deflection type instrument b)null type instrument

)deflection as well as nulltype instrument d)digital instrument

2.)When a potentiometer is used for measurement of voltage of an unknownsource,the power consumed

in the circuit of the unknown source under null conditions[ d ]

a)is very high b)is high c)is small d)is ideally zero

3.)Standardization of potentiometer is done in order that ,they become[ d ]

a)accurate b)precise c)accurate and precise d)accurate and directreading

4.)The standardization of AC potentiometer is one by[ b ]

a)directly using AC standard voltage sources


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b)Using DC sources and transfer instruments

c) Using AC sources and transfer instruments

5.)Potentiometers used in control systems are[ c ]

a)To improve stability b)To improve frequency response

c)As error sensing transducers d)To improve time response

6.)In order to achive high accuracy, the slide wire of a potentiometer should be[ a ]

a)As long as possible b)As short as possible

c)neither too small nor too large d)very thick

7.)By using potentiometers we can measure[ c ]

a)High voltages b)voltages greater than 100V

c)voltages less than 2V d)None

8.)A dc potentiometer is designed to measure up to 2V with a slide wire of 800mm.Astandard cell emf 1.18V obtains balance at 600cm.A test cell is seen to obtainbalance at 680mm.The emf of test cell is [ b ]

a)1.00V b)1.34V c01.50V d)1.70V

9.)The reading of a polar type AC potentiometer when measuring the reactance of acoil are

I=12 ,V=27.8 .The reactance of a coil is [ b]

a)2.317 b)0.634 c)2.22 d)-2.22

10.)In the potentiometer circuit shown in the figure. balance is obtained. Theunknown emf is. [ a ]


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a)200mV b)2.8mV c)3.0mV 400mV


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UNIT - V

1.Draw the circuit of a Kelvins double bridge used for measurement of low resistances.Derive the conditions for balance.

2. A 4terminal resistor approximately of 50 resistances was measured by means of Kelvindouble bridge having the following component resistances:

standard resistor=100.02 ; Inner ratio arms=100.30 and 200 ; Outer ratioarms=100.23 and 200

Resistance of link connecting the standard and the unknown resistance is 700 .Find unknown resistance

3.Derive the equation of balance for an Andersons bridge .Draw the phasor diagra m forconditions under balance.

Discuss the advantages and disadvantages of this bridge.4.Obtain the balancing conditions for the schering bridge with its phasor diagram.

BITS

1.)The common bridge for precise measurement of inductance over a wide range is []

a)Maxwells bridge b)Hays bridge c)Anderson bridge d)None


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2.)The bridge most commonly employed for measurement of frequency is []

a)Owens bridge b)Hays bridge c)schering bridge d)Weins bridge



4.)Which one of the following is measured by the loss of charge method []


5.)High resistances are in the range of [ ]




8.)The continuity in underground cables can be detected by using_______________.9.)The low resistance is in the range of____________________.

10.)The high resistance is in the range of from __________to_______________.


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UNIT-VI

1.Explain the determination of B-H loop method of reversals.

2.Discuss the constructional details of Ballistic galvanometer?

3.)Explain the construction details and operation of the flux meter?

4.) Explain the determination of B-H loop by step by step method?

BITS

1) Paramanent magnets are tested by [ ]



2.)The construction of Fluxmeter is similar to ____________milli ammeter []


3.)The loop which represents the relation of B & H is []


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a) Hysteresis loop b)Eddy current loop c)closed loop d) None

4.)A multimeter is used to measure [ ]a)resistance b)Voltage c)Current d)all of the above

5.)The unit of flux is[ ]

a)Weber b) Tesla c) Newton d) Joul

6) The flux meter have__________ damping torque __________ control torque.

7) If hysteresis loop of a particular material is widen then the permittivity of the material __________

8) As air gap increases the reluctance becomes________________.

9) Permanent magnets are tested by_______________.

10.) In Ballistic galvanometer the controlling Torque is_____________.


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UNIT-VII

1. How the phase and frequency can be measured with the use of a CRO. Explain?

2.Explain the functions of the following controls:


iii). Horizontal and vertical positioning iv). Synchronization

3.What ate the applications and advantages of the CRO?

4.Explain the functions of the vertical and horizontal amplifiers in the CRT tube?

BITS

1.) A dc voltage of 1V is applied to the X-plates of a CRO and ac voltage 2sin100t is appliedto the Y-plates

The resulting display on the CRO screen will be [ ]


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2)While measuring the phase difference between the V 1(t)=10sinwt and V 2(t)=10 sin(wt+),the Lissajous pattern observed on CRO was a circle. The value of is [ ]a)zerob)/4 c)/2 d)

3.) A certain oscilloscope with 4cmX4cm screen has its own sweep output fed to its input.Ifthe X and Y sensitives are same ,the oscilloscope will display a [ ]a)sawtooth b)triangular c)diagonal line d)horizontal line

4.)The X and Y inputs to a CRO are respectively 10cos(wt +) and 10sin(wt +) . The

resulting Lissajous pattern is[ ]


5.)Voltages V y=100sin100t and V x=50sin100t are connected to Y and X terminals of a CROrespectively. What is the shape of the screen on the CRO[ ] a)Circle b)straight line c)Anellipse d)A parabola



7.)The material used in the CRT screen[ ] a)Zinc b) Phosphorous c) Molybdenum d.)copper

8.)The Lissajous patterns can be used to find the___________________.

9.)The CRT of the Television can be worked on the _____________________ principle.

10.)_______________ system can be used as intensity knob.


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UNIT-VIII

1. Explain the method of measuring voltage in successive approximation method.

2. Explain the operation of the ramp type DVM?

3. What are the applications and advantages of digital instruments?

4. Explain the working and operation of digital multimeters?

BITS

1.)A multimeter is used to measure []


2.)Digital instruments deals with ___________ voltage

[ ]

a)Low b) High c) Moderate d) None

3.) Digital instruments deals with ___________ frequency[ ]

a)Low b) High c) Moderate d) None


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4.) By using successive approximation method we can measure[ ]

a) voltage b) current c)power d)none

5.) The accuracy in case of digital instruments compared with analog instruments is[ ]

a)more b)less c)none of these

6.) The voltage can be measured by ___________ method.

7) If hysteresis loop of a particular material is widen then the permittivity of the material __________

9) As air gap increases the reluctance becomes________________.

10.) If hysteresis loop of a particular material is widen then the permittivity of the materialis


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Previous years question papers JNTUA

IIIB. TechI Semester (R09)Regular Examinations,November 2011ELECTRICAL&ELECTRONIC MEASUREMENTS

(Electrical &Electronics Engineering)


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Time:3hours MaxMarks:70 AnsweranyFIVEquestions

All questionscarryequal marks*****

1 (a) Explainhowthecurrent rangeofPMMC instrumentisextendedwith thehelpofshunts. (b) Discussabout ErrorsandCompensationsof measuringinstruments.

2 (a) Listtheadvantagesanddisadvantagesofinstrumenttransformers. (b) Discussphaseangleerror.

3 (a) Explaindrivingsystem,movingsystemandbreakingsystemina1- inductiontype energymeter.

(b) Writeshortnotesonthreephaseenergymeter.

4 (a) Writeshortnotesonpolarstandardization. (b) Explain theoperationof DC Crompton spotentiometer.

5 (a) Withneat figureexplain theworkingofawheatstone sbridge. (b) Howdoyou measureinductanceusingMaxwell sbridge?

6 (a) DiscussA.Ctesting. (b) Writeexplanatorynotesonfluxmeter.

7 (a) Withneat figureexplain theworkingofa CRO. (b) Howdoyou measurephaseandfrequency usingCRO?

8 (a) Explain thefunctionofdigitaltachometer. (b) Discusstheworkingofanintegrating typevoltmeter.

*****


73/160


(Electrical &Electronics Engineering)Time:3hours MaxMarks:70


*****

1 (a) Explain themethodofreducingerrors in measuringinstruments. (b) Withaneatfigureexplaindynamometer.

2 (a) Explain theworkingofadynamometer. (b) DiscussCTand PT.

3 (a) Explain themeasurementofLPFandUPF. (b) Whatisthesignificanceofdrivingandbreakingtorquesina1- inductiontypeenergy

meter?

4 (a) Explain themeasurementofunknown resistanceusingDC Crompton spotentiometer. (b) Listtheapplicationsofpotentiometer.

5 (a) Explain themeasurementofhighresistance-loss ofchangemethod. (b) Explain theworkingofAndersonbridge.

6 (a) Explain thedeterminationofB-H loopmethodof reversals.

(b) WriteshortnotesonLissajouspattern. 7 (a) Explain theconstructional detail andworkingofa CRT.

(b) ListtheapplicationsofCRO.

8 (a) Explain theworkingofadigitalfrequencymeter. (b) Listtheadvantagesof digital voltmeter.

*****


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(Electrical &Electronics Engineering)Time:3hours MaxMarks:70


*****

1 (a) Deriveanexpressionforthedeflecting torqueandcontrol torque. (b) Give thegeneral requirementsfor theconstructionofshunts.

2 (a) Discussthedifferent errorsofPMMC. (b) Withneat figureexplain thefeaturesofmovingiron typePFmeter.

3 (a) What isaphasemeter? Discussthemeritsanddemeritsofit. (b) Withaneat sketchexplain theworkingofasinglephasedynamometer wattmeter.

4 (a) Withneat figureexplain theworkingofanACpotentiometer. (b) Discussthesignificanceofstandardization.

5 (a) Howdoyou measurecapacitanceusingWien sbridge? Explain. (b) Explain thesensitivityofwheatstone sbridgeandhowdoyou measureit.

6 (a) DiscusstheconstructionaldetailsofBallisticgalvanometer. (b) ListtheapplicationsofCRO.

7 (a) Howdoyou measurecurrent andvoltageusingCRO? (b) Discusshorizontal andvertical amplifiersofCRO.

8 (a) Explain themethodofmeasurementofvoltageusingRamp typevoltmeter. (b) Listtheadvantagesof digitalmultimeter and limitationsof thesame.

*****


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IIIB. TechI Semester (R09)RegularExaminations,November 2011

ELECTRICAL&ELECTRONICMEASUREMENTS (Electrical

&Electronics Engineering)Time:3hoursMaxMarks:70

AnsweranyFIVEquestions

Allquestionscarryequal

marks

1 (a) Explain theworkingofauniversal shuntusedfor multirangeammeter. (b) Writethesignificanceof controlanddamping torques.

2 (a) Define transformation ratio, nominal ratio and turns ratio as used for instrumenttransformers. (b) Listtheadvantagesanddisadvantagesof movingirontypeinstruments.

3 (a) Discusstheerrorsandcompensationofsinglephaseenergymeter. (b) Obtaintheexpressionfordeflectingandcontroltorquesofadoubleelementwattmeter.

4 (a) Howdoyou measurecurrent andvoltageusingpotentiometer? (b) Discusscoordinatetypeofstandardization.

5 (a) Explain theworkingofa Kelvin sdoublebridgefor measuringlowresistance. (b) Explain thefeaturesofDesautybridgewithaneat sketch.

6 (a) Derive theequationofmotioninBallisticgalvanometer. (b) Explainsixpointmethods.

7 (a) What doyou meanbyLissajouspatterns? Howdoyou measurethem usingaCRO? (b) Drawaneat figureandexplain theworkingofaCRO.

8 (a) Explain themethodofmeasuringvoltage insuccessiveapproximation method. (b) Givesalient featuresofdigitalmultimeter.

*


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Electrical Machines _III

Syllabus

JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY ANANTAPUR


4 0 4

(9A02505) ELECTRICAL MACHINES - III

UNIT I CONSTRUCTION AND PRINCIPLE OF OPERATIONConstructional Features of round rotor and salient pole machines Armature windings Integral slotand fractional slot windings; Distributed and concentrated windings distribution, pitch and windingfactors E.M.F Equation.

UNIT-I SYNCHRONOUS GENERATOR CHARACTERISTICS

Harmonics in generated e.m.f. suppression of harmonics armature reaction - leakage reactance synchronous reactance and impedance experimental determination - phasor diagram load

characteristics.

UNIT III REGULATION OF SYNCHRONOUS GENERATORRegulation by synchronous impedance method, M.M.F. method, Z.P.F. method and A.S.A. methods salient pole alternators two reaction analysis experimental determination of X d and Xq (Slip test)Phasor diagrams Regulation of salient pole alternators.

UNIT IV PARALLEL OPERATION OF SYNCHRONOUS GENERATORS

Synchronizing alternators with infinite bus bars synchronizing power torque parallel operation andload sharing - Effect of change of excitation and mechanical power input. Analysis of short circuitcurrent wave form determination of sub-transient, transient and steady state reactances.

UNIT V SYNCHRONOUS MOTORS PRINCIPLE OF OPERATION

Theory of operation phasor diagram Variation of current and power factor with excitation V andInverted V Curves - Power developed Synchronous Condenser.

UNIT-VI POWER CIRCLES


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Excitation and power circles hunting and its suppression Methods of starting synchronousinduction motor.

UNIT VII SINGLE PHASE MOTORS

Single phase induction motor Constructional features - Double revolving field theory Elementary

idea of cross-field theory split-phase motors shaded pole motor.

UNIT VIII SPECIAL MOTORS

Principle & performance of A.C. Series motor-Universal motor Principle of permanent magnet andreluctance motors.

TEXT BOOKS

1. Electric Machines by I.J.Nagrath & D.P.Kothari, Tata Mc Graw-Hill Publishers, 4 th Edition, 2010.

2. Electrical Machines by P.S. Bimbra, Khanna Publishers.

REFERENCE BOOKS:

1. The Performance and Design of A.C.Machines by M.G.Say, ELBS and Ptiman & Sons.2. Electric Machinery by A.E. Fitzgerald, C.Kingsley and S.Umans, Mc Graw-Hill Companies, 5 th

edition, 1990.3. Theory of Alternating Current Machinery by Langsdorf, Tata Mc Graw-Hill, 2 nd edition.4. Electromachanics-III (Synchronous and single phase machines), S.Kamakashiah, Overseas publishers

Pvt Ltd.5. Electric Machines - by M. S. Sarma and M. K. Pathak, CENGAGE Learning.


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Objective

ELECTRICAL MACHINES III

Objective :

This subject is an extension of previous machines courses. It deals with the detailed analysis of

Synchronous generators and motors which are the prime source of electrical power generation and its

utilities. Also concerns about the different types of single phase motors which are having significant

applications in house hold appliances and control systems.

Synchronous generators are the prime source of electrical power generation in many power plants. In

our INDIA, the highest rating of 3-ph alternator for generating 3-ph AC power is 500MW at voltage range

of 6.6KV to 33KV with 50 Hz cycles/sec

In industry, most of the machines for different applications are 3-ph Induction motor, only a small

amount synchronous machines are used for some special purposes because of its excellent advantages.

The main advantages of 3-ph synchronous motors are it is used as synchronous condenser for power

factor correction, for improvement of voltage regulation in power system, used to drive constant speed

drives of loads etc.

There are two basic reasons for the use of 1-ph motors than 3-ph motors. Those are (i) For the reason

of economy, most houses, offices and also rural areas are supplied with 1-ph ac power. (ii) Economy of

motor and its branch circuit. The 1-ph m/cs are simple in construction, reliable, easy to repair, cheaper

in cost etc.


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Lesson Plan

PBR VISVODAYA INSTITUTE OF TECHNOLOGY & SCIENCE

ACADIMIC YEAR: 2013 14 CLASS: III B.Tech-EEE Faculty Name : P. Gopi

LESSON PLAN Subject: EM-III

S.No.

Dates

No.ofperiods

In week

Topic to be covered

No.of

Periods

required

Total

Periods

Per

unit

1 2Basic laws in electrical engg. and introduction

to electrical machines 202

09

2 4

Unit-I

Operating principle and working

Constructional Features of round rotor andsalient pole machines

Armature windings Integral slot andfractional slot windings; Distributed andconcentrated windings

1

1

2

3 5

Distribution, pitch and winding factors

E.M.F Equation.

212


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Problems solved

10

11

08

4 5

Unit-II

Harmonics in generated e.m.f.

suppression of harmonics

Problems solved

Armature reaction

112

1

5 5

Leakage reactance synchronous reactanceand impedance

Experimental determination

Phasor diagram load characteristics.

Problems solved

1112

6 3

Unit-III

Regulation by synchronous impedancemethod and problems solved.

M.M.F. method

21

7 5

Problems solved on M.M.F. method

Z.P.F. method and A.S.A. methods andproblems solved

Salient pole alternators two reaction analysis

1

31

8 5

Experimental determination of X d and Xq (Sliptest) Phasor diagrams

Regulation of salient pole alternators.

Unit-IV

Synchronizing alternators with infinite bus

bars

Synchronizing power torque

12

11

9 5

Parallel operation and load sharing

Effect of change of excitation and mechanicalpower input.

12

1


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Analysis of short circuit current wave form

Determination of sub-transient, transient andsteady state reactances.

1

02.09.13 TO 07.09.13 1 ST MI D EXAMS

10 2Revision of Mid paper IIntroduction to Sym. Motors

11

02

09

06

08

06

11 5

Unit-V

Theory of operation phasor diagram

Types of excitation systemsVariation of current and power factor withexcitationV and Inverted V Curves

112

1

12 5

Power developed and problems solved

Synchronous Condenser and problems solved

Unit-VI

Hunting and its suppression

2

2

1

13 5

Excitation and power circles

Methods of starting

Synchronous induction motor.

221

14 4

Unit-VII

Single phase induction motor

Constructional features

Double revolving field theory and cross-fieldtheory

11

2

15 2

Split-phase motors

Shaded pole motor.

11

16 5

Problems solved

Unit-VIII

Principle & performance of A.C. Series motor

Universal motor

2

21

17 5 Principle of permanent magnet 1


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Reluctance motors.

Problems solved

Revision

112

No. of periodsavailable 72 No. of periods required 72

TEXT BOOKS:

1. Electric Machines by I.J.Nagrath & D.P.Kothari , Tata Mc Graw-Hill Publishers, 4 th Edition, 2010.

objective question paper

Documents