III YR -EEanucde.info/DEC2014QPS/36-3.pdf5) a) List out the advantages and disadvantages of corona....

(DEE311)

B.Tech. DEGREE EXAMINATION, NOV./ DEC. 2014

(Examination at the end of Third Year Third Semester)

ELECTRICALS AND ELECTRONICS

Paper - I: Linear Control Systems

Time : 3 Hours Maximum Marks: 75

Answer question no.1 compulsory (15)

Answer ONE question for each unit (4×15=60)

1) a) What are poles of a system?

b) Define Band Width.

c) What are coordinate axes for root locus?

d) What is the use of lead compensator?

e) Write state model of a system.

f) What is feed back?

g) What is multivariable system?

h) What is regulator?

i) What is lag compensator?

j) What are the advantages of frequency domain response?

k) Define sensitivity.

l) Define non linear system.

m) State the rule for shifting the summing point ahead of a block.

n) What is the effect of positive feed back of stability?

o) Compare the step responses of first order and second order systems.

UNIT - I

2) Determine the transfer function C(S)/ R(S) of the system shown below fig, by block

diagram reduction method.

(OR)

3) For the signal flow graph shown below fig; find overall gain.

UNIT – II

4) a) Draw the time response characteristic of a typical 2nd order system and denote salient

points on it.

b) Find the transfer function of a second order system with peak time tp of π/12 sec. and

a maximum overshoot µp of 0.095.

(OR)

5) Explain Routh hurwitz criterion.

UNIT - III

6) a) What are the rules for construction of root locus.

b) Explain nyquist stability criterion.

(OR)

7) Draw Bode plot for the system. ( )( )2

36(1 0.2S)G(S)=

S 1 0.05S 1 0.01S

++ +

UNIT - IV

8) a) Explain the effect of lag compensation on system’s response.

b) What are the properties of state transition matrix?

(OR)

9) a) If 0 1

A0 1

=

find the state transition matrix.

b) Explain the term controllability.

(DEE312)

B.Tech. DEGREE EXAMINATION, NOV./ DEC. - 2014



Paper - II : Electronic Circuits-II


Answer Question no.1 is compulsory (15)

Answer one question from each unit (4× 15=60)

1) a) Define ‘Distortion’.

b) What is a heat sink and list the types of heat sinks?

c) What do you mean by conversion efficiency?

d) What do you mean by Piezo electric effect?

e) Give 3 differences between positive feedback and negative feedback.

f) What do you mean by hysteresis voltage in Schmitt trigger?

g) List the applications of Bistable multivibrator.

UNIT - I

2) a) Explain harmonic distortion in power amplifier.

b) Draw the circuit diagram, output characteristics of a simple (series – fed) class A – Power

amplifier and obtain the output power equation.

OR

3) a) Explain the working of a Push pull (class B) amplifier.

b) What is thermal resistance and give its significance.

UNIT – II

4) a) Explain the circuit diagram of a negative feedback and obtain expression for its closed

loop gain.

b) Explain the principle of operation of Weinbridge oscillator.

OR

5) State the condition of (1+Aβ) for which a feedback amplifier must satisfy in order to be stable.

UNIT - III

6) a) Draw a neat figure and explain the operation of a class C amplifier.

b) Draw the circuit diagram of Bistable multivibrator using BJT and explain its operation.

OR

7) a) Draw the Schmitt trigger circuit and explain with waveforms.

b) Explain the operation of a tuned primary amplifier.

UNIT - IV

8) a) Explain the different protection techniques in Regulated power supplies.

b) Write short notes on UPS.

OR

9) a) Explain the steps involved in design of Voltage regulators and list its applications.

b) Write short notes on current sweep circuits.

(DEE313)

B.Tech. DEGREE EXAMINATION, NOV./ DEC. 2014



Paper - III: Generation of Electrical Power


Answer question no.1 compulsory (15)

Answer any ONE question from each unit ( 4×15=60)

1) a) Explain utilization factor.

b) What is tariff?

c) Define solar constant.

d) What is meant by PV cell?

e) Define plant use factor

f) Define tidal energy.

g) Define diversity factor.

h) Define Surge tank.

i) Define Run off.

j) What is cold reserve?

k) What is cavitation?

l) What is meant by Running charges?

m) Define peak load.

n) What is economiser in steam plants?

o) List some nuclear fuels.

UNIT - I

2) Explain the following:

a) Choice of generation.

b) Size of generator units.

c) Superheater.

OR

3) Draw and explain typical layout of thermal power plant.

UNIT – II

4) a) Explain how the site is selected for hydro electric stations.

b) Explain the working of pumped storage plant for peak load.

OR

5) Explain different nuclear reactors briefly.

UNIT - III

6) a) Explain various components of gas turbine plants.

b) Explain the construction and working of a solar cell.

OR

7) a) Derive an expression for the torque and total power generated in wind

turbines.

b) Explain how the power is extracted from the tides.

UNIT - IV

8) a) Derive an expression for the most economic power factor.

b) Discuss various costs go into the generation of electric energy.

OR

9) Discuss the causes, effects of low power factor. Explain various methods of

power factor improvement.

(DEE314)

B.Tech. DEGREE EXAMINATION, NOV/ DEC 2014



Paper - IV : Electrical Measurements


Question No.one is compulsory (15)

Answer any one question from each unit (4× 15=60)

1) a) What is the advantage of Electrostatic instruments?

b) What is basic classification of instruments?

c) What is the use of a Synchronoscope?

d) What are the various techniques used for producing control torque?

e) Which instrument can be used as transfer instrument?

f) Write the expression for % ratio error in a potential transformer.

g) What are the major errors occurring in current transformer?

h) Write the expression for unknown inductance in Hay’s Bridge.

i) State advantages of Carey Foster Bridge.

j) Define permeability.

k) What are the different modes of operations in oscilloscopes?

l) What is the basic function of Ballistic galvanometer?

m) What is a transducer?

n) What is the principle of operation of LVDT?

o) What are the applications of Kelvin’s double bridge?

UNIT - I

2) Explain the methods for measuring power in both single phase and three phase circuits.

OR

3) a) Discuss the principle of operation of electrostatic voltmeters.

b) What are the essential torques required for operating any instrument?

UNIT – II

4) a) Explain how do you extend the range of voltmeter.

b) A 1000/5A, 50Hz current transformer has a secondary burden comprising a non inductive

impedance of 1.6Ω. The primary winding has one turn. Calculate the flux in the core and

ratio error at full load. The magnetizing mmf is 100A.

OR

5) Derive the equations of balance for an Anderson’s bridge. Draw the phasor diagram for

conditions under balance. Discuss the advantages and disadvantages of the bridge.

UNIT - III

6) Describe the methods for determination of B.H curve of a magnetic material using

(i) Method of Reversals and (ii) Step by step method.

OR

7) a) Explain the method for measurement of iron losses using Epstern’s square.

b) Discuss about calibration by Hibbert’s magnetic standard.

UNIT - IV

8) a) Explain the theory and working of LCDs.

b) Describe the difference between light scattering and field effects types of LCDs.

Also explain the advantages of LCDs.

OR

9) a) Describe the construction and working of thermocouple.

b) List out advantages and disadvantages of LVDT.

(DEE 315)

B.Tech. DEGREE EXAMINATION, NOV./DEC. – 2014

(Examination at the end of Third Year and Third Semester)


Paper - V : Transmission & Distribution

Time : 3 Hours Maximum Marks : 75

Answer Question No.1 is Compulsory (15)

Answer ONE question from each unit (4 × 15 = 60)

1) a) What is bundling of conductors?

b) What is meant by sag?

c) Define insulation?

d) What is Ferranti effect?

e) How substations are classified?

f) What are the characteristics required for a surge arrestor.

g) Define the term feeder and service mains.

h) Define GMD and GMR.

i) Limitation of Kelvin’s law.

j) Explain Transposition of conductors.

k) Why grading of cables is more of theoretical interest than practical.

l) Define carona.

m) List out advantages of bundled conductors.

n) Various methods of earthing in substations.

o) Define string efficiency.

UNIT - I

2) a) Derive an expression for inductance per phase of a 3 phase symmetrically spaced

transmission line.

b) Explain briefly factors affecting corona.

OR

3) a) A 3φ, 132kv line has conductors each of 2 cm diameter and arranged in a horizontal

plane as shown in fig. below. Find the surge impedance of the line per phase.

Assume the line to be transposed.

b) Derive an expression for capacitance of a 3 ph transmission line with unequal

spacing assuming uniform transposition.

UNIT – II

4) a) Classify the transmission lines based on line length and operating voltages.

b) What is Ferranti effect? Deduce an expression for voltage rise of an unwaded line .

OR

5) a) List out the advantages and disadvantages of corona.

b) Explain the effect of wind and ice on sag.

UNIT - III

6) a) Explain the connection schemes of distribution system.

b) Derive an expression for the power loss in a uniformly loaded distributor fed at one

end.

OR

7) a) Explain the indoor and outdoor substation.

b) Briefly discuss the equipments of substation.

UNIT - IV

8) a) Derive an expression for voltage distribution over a string of suspension insulators.

b) Write a short note on insulator failure.

OR

9) a) What are the methods of equalizing the potential?

b) A string of six insulator units has mutual capacitance 10 times the

capacitance to ground. Determine the voltage across each unit as a fraction of the

operating voltage. Also determine the string efficiency.

(DEE 316)




Paper - VI : Electro Mechanics - III




1) a) What is step bearing?

b) What is the main disadvantage of using short - pitch winding in alternators?

c) Why are 3-phase alternators invariably star-connected?

d) What is the purpose of power drawn by the prime mover of an alternator under no-

load condition?

e) What is a synchronous capacitor ?

f) What are reasons for failing to start a synchronous motor?

g) What is the maximum value of torque angle in a synchronous motor?

h) What is breakaway torque?

i) At what power factor, armature current is minimum in a synchronous motor.

j) What is a Universal motor?

k) Do stepper motors have internal or external fans?

l) What is the efficiency of the tiny motor used in a wrist watch?

m) What are the applications of a reluctance motor?

n) What is the principle of operation of linear induction motor?

o) List any applications of stepper motor.

UNIT - I

2) a) Discuss pitch factor and spread factor in detail with necessary diagrams and

equations.

b) Calculate pitch factor for the under - given windings : (i) 36 stator slots, 4 poles, coil

span, 1 to 8 (ii) 72 stator slots, 6 poles, coils span 1 to 10.

OR

3) a) Discuss any method for determining voltage regulation in an alternator.

b) What are the variable losses that occur in an alternator? Derive the

expression for efficiency.

UNIT – II

4) a) Derive the expression for synchronising power in an alternator.

b) What are the essential conditions for operating alternators in parallel?

OR

5) a) Find the power angle when a 1500 kVA, 6.6kV, 3-φ, Y-connected alternator having a

resistance of 0.4 ohm and a reactance of 6 ohm per phase delivers full-load current at

normal rated voltage and 0.8 p.f lag. Draw the phasor diagram.

b) Explain how slip test is conducted on alternators?

UNIT - III

6) a) Explain the principle of operation of synchronous motor?

b) Explain the methods for starting a synchronous motor?

OR

7) a) Explain the procedure for constructing V-curves in a synchronous motor.

b) What is a synchronous condensor? Discuss & list out its applications.

UNIT - IV

8) a) Explain the principle of operation, working and applications of Universal motors?

b) What are the different types of repulsion motors? Discuss about the principle of

repulsion in repulsion motors?

OR

9) a) Explain the principle and working of variable reluctance stepper motor.

b) Discuss the advantages and disadvantages of different modes of operation of variable

reluctance stepper motors.

(DEE 321)


(Examination at the end of Third Year Fourth Semester)


Paper - I : Linear IC’s & Applications




1) a) Define offset current and offset voltage.

b) What is the relation between gain and BW?

c) Why emitter follower is used at the third stage of block diagram of OP-AMP.

d) Differentiate ideal OP-AMP to that of practical OP-AMP.

e) Different modes of operation of differential amplifier.

f) Why common mode signal is not preferred in OP-AMP.

g) What do you mean by phase shift, why the name for phase shift oscillator.

h) Which type of feedback is preferred in Oscillator justify your answer.

i) Describe the real time applications of peak detector.

j) Mention any two applications of Tracking A/D converter.

k) Advantages of Active filters over passive filters.

l) Define state variable filter.

m) Purpose of voltage regulator, explain.

n) What does the order of filter represents explain.

o) Define Multiple feedback Band pass filters.

UNIT – I

2) a) Design an OP-AMP differentiator to differentiate an input signal that varies in

frequency from 10Hz to about 1KHz. .

b) Explain the principle of operation of precision full wave rectifier with waveforms.

OR

3) a) Discuss in detail all the DC and AC characteristics of an ideal OP-AMP with

relevant expressions.

b) Differentiate ideal integrator & practical integrator.

UNIT - II

4) a) Draw the schematic diagram of Wien Bridge Oscillator and derive the

expression for frequency of oscillation.

b) Discuss about high speed and precision type comparators. And explain its

applications .

OR

5) a) Derive the frequency of oscillation of a RC phase shift oscillator and explain the

operation of the circuit.

b) Discuss about

i) Zero crossing detector

ii) Window detector with its applications.

UNIT - III

6) a) What is a clipper? With the circuit explain the operation of positive and negative

clipper.

b) What do you mean by sampling? Explain the basic circuit of sample and hold circuit.

c) Draw the circuit diagram of successive approximation ADC and explain its

operation. Mention its applications.

OR

7) a) What is a clamper? With circuit diagram explain the operation of positive and

negative clampers.

b) Draw a schematic diagram of a DAC converter. Use resistance values whose ratios

are multiples of 2. Explain the operation of the converter.

c) Explain the operation of peak detector.

UNIT - IV

8) a) What are the two basic modes in which the 555 Timer operates? Briefly explain the

differences between the two operating modes of the 555 Timer.

b) Discuss the procedure to design Fourth order Butterworth Filter.

OR

9) a) Explain an application of 555 Timer as an Astable multivibrator.

b) What is PLL, and its operation? Explain analog phase detector Role in PLL.

c) Describe the 2nd order HPF design procedure.

(DEE 322)




Paper - II : Microprocessors & Interfacing


Answer Question No.1 Compulsory (15)


1) a) What does ‘CF’ perform in Flag register.

b) What do you mean by program memory.

c) What is a ‘TRAP’ instruction.

d) Give example for ‘HLDA’.

e) What is an idle state.

f) Give an example of ‘Indexed’ addressing mode.

g) What does ‘NMI’ perform.

h) What is interfacing.

UNIT – I

2) a) Discuss the addressing modes of 8086.

b) Draw and explain the 8086 internal architecture.

OR

3) a) Distinguish between microcomputers and microprocessors.

b) Explain HOLD, JUMP, HLDA and LEA instructions with suitable examples.

UNIT - II

4) a) Write an ALP to add two 16 bit numbers.

b) Discuss SBB, AAD and SCAS instructions of 8086.

OR

5) a) Write the differences between ALP and MLP.

b) Discuss the minimum mode control signals of 8086.

UNIT - III

6) a) What is the difference between RET and IRET. Discuss the result if RET instruction

is placed at the end of interrupt service routine.

b) How do you interface a micro processor to a keyboard.

OR

7) a) What is the vector address of type 50H interrupt.

b) Give the A/D converter specifications and how is it interfaced with 8080 µ p.

UNIT - IV

8) a) Explain 8053 interfacing with 8086.

b) Explain 8259 architecture and how it is programmed.

OR

9) a) Explain 8259 architecture.

b) Discuss the DMA data transfer.

(DEE 323)

B. Tech. DEGREE EXAMINATION, NOV./DEC. – 2014


ELECTRICALS & ELECTRONICS

Paper - III : Digital Signal Processing


Question No.1 is compulsory (15)

Answer ONE Question from each unit (4 ×15 = 60)

1) a) Define Stability and Causality.

b) Define ROC and draw the same.

c) List properties of DFT.

d) Give advantages of Digital Design of filters.

e) What are the advantages of windowing methods?

f) Define Nyquist theorem.

g) Draw a non – stationary signal.

h) What is Reverberation?

UNIT – I

2) a) Check whether ∑−

==

1N

0

)X(N

1)(

m

n-mny is linear.

b) Find the inverse z transform using partial fraction expansion

OR

3) a) Determine the sequence corresponding to the following frequency domain

representation.

X (ejw) = 1

= 0 ΠW b) With reference to z transform, state the initial and final value theorem.

UNIT – II

4) a) Define DFT of a sequence X(n). Obtain the relationship between DFT and DTFT.

b) Calculate the number of multiplications needed in calculation of DFT using FFT

algorithm with 32 point sequence.

OR

5) a) Prove the modulation and time shifting properties of DTFT.

b) Compute the FFT of the sequence 0,0 0,1,0,0,0,0,X(n) =

UNIT – III

6) a) Describe digital IIR filter characterization in time domain.

b) Compare Butterworth and Chebyshev approximations.

OR

7) a) Design low pass Butterworth filter that has a 3dB Cut off frequency of 1.5kHz and

an attenuation of 40 dB at 3kHz.

b) Discuss the properties of Bilinear transformation method.

UNIT – IV

8) a) Determine the frequency response of linear phase FIR filter given by y(n) =A1

x(n)+ A2x(n-1)+A3x(n-2)+A2x(n-3)+A1 x(n-4).

b) Explain FIR filter design using windowing method.

OR

9) a) Write the magnitude and phase functions of FIR filter when impulse response is

symmetric and N is even.

b) Realize using Direct form II

y(n) =(3/4) y(n-1) – (1/8) y(n-2) + x(n) + (1/3) x (n-1)

(DEE 324)




Paper - IV : Power Electronics


Answer Question No.1 is compulsory (1×15 = 15)

Answer one question from each unit (4×15 = 60)

1) a) What is meant by delay time of an SCR.

b) What is communication.

c) What is firing angle.

d) What is the necessity of free wheeling diode.

e) What are the applications of dual converters.

f) Explain the principle of Inverter.

g) What is a cyclo converter.

h) Draw the gate characteristics of an SCR.

i) What is snubber circuit.

j) What is a LASER.

k) What is meant by distortion factor in spwm.

l) What is meant by modulation index.

m) What are different types of inverters.

n) Define avalve.

o) What is a dual converter.

UNIT - I

2) a) Discuss about the series operation of thyristors.

b) Explain the different turn-on methods of thyristors.

OR

3) Explain the operation of MOSFET and IGBT.

UNIT - II

4) Describe the working of single phase fully controlled bridge converter in the Rectifying

mode and inversion mode. And derive expressions for average output voltage and rms

output voltage.

OR

5) Describe the working of 3ph half controlled converter for α = 30o with relevant waveforms

and derive expression for average output voltage.

UNIT - III

6) Explain the operations of McMurray full bridge inverter in details with reference to

different modes of operation. What are its applications.

OR

7) Explain the operation of 3ph bridge inverter for 180o mode of operation with aid of

relevant phase and line voltage waveforms.

UNIT - IV

8) Explain in detail the principle of operation single phase cyclo converters.

OR

9) Describe the principle of step up chopper. Derive an expression for the average output

voltage in terms of input dc voltage and duty cycle.

(DEE 325)




Paper - V : Utilization of Electrical Power


Answer Question No.1 is compulsory (15)

Answer any one question from each unit (4×15 = 60)

1) a) What is regenerative braking.

b) What is short time loading.

c) What is stefan’s law.

d) Define luminance.

e) What is MHCP.

f) What is resistance welding.

g) What is traction systems.

h) What is Kando system.

i) What is overload capacity of inducting motors.

j) What is the advantage of dielectric heating.

k) Define electric drive.

l) Define plugging.

m) Define torque.

n) Define crest speed.

o) What is cooling of motor.

UNIT - I

2) a) What are the advantages of electric drive.

b) What are the factors governing the selection of motors.

OR

3) a) Explain the flywheel and its applications in load equalisation.

b) Write short notes on selection of capacity for short time and intermittent periodic duty.

UNIT - II

4) What is speed time curve and deduce expressions to get the relationship between various

quantities using a) trapezoidal. b) quadrilateral speed time curves.

OR

5) a) Explain how the direction of rotation of traction motor is reversed.

b) What is kando system. Explain the potentialities of this systems for its being adopted.

UNIT - III

6) a) What are the advantages of electric heating.

b) What are the requirements of good heating element.

OR

7) a) Derive the expression for design of heating element.

b) What are different types of electric welding explain.

UNIT - IV

8) a) What are the four demerits of gaseous discharge lamp.

b) Explain the principle of operation of sodium vapour lamp.

OR

9) a) What are the various factors to be considered in the design of factory lighting.

b) Explain in detail about flood lighting.

(DEE 326)




Paper - VI : Switch Gear & Protection


Answer Question No.1 is compulsory (1×15 =15)

Answer any ONE Question from each unit (4×15 = 60)

1) a) Define plug setting multiplier.

b) Define current chopping.

c) What is meant by neutral grounding.

d) Define earth resistance.

e) Define amplitude comparators.

f) Define setting value.

g) Define reach.

h) What is meant by recovery voltage.

i) Define the term burden.

j) What is static relays.

k) What is a circuit breaker.

l) What are the requirement of time protection.

m) Define restraining force.

n) What are the factors which influence the arc voltage.

o) What is a protective relay.

UNIT - I

2) a) What are the various protective schemes in switch gear and protection.

b) Explain Buchholz’s relay with a neat sketch.

OR

3) Explain briefly electromechanical relays with a neat sketch.

UNIT - II

4) a) Explain SF6 circuit breaker with a neat sketch.

b) What are the elementary principles of arc phenomenon.

OR

5) a) Explain the construction of working of vaccum circuit breakers.

b) Explain the specifications of a circuit breaker.

UNIT - III

6) a) With a neat diagram explain differential protection for generators.

b) Explain Translay relay with neat sketch.

OR

7) a) What are the objectives of earthing.

b) Explain the solid grounding with neat sketch.

UNIT - IV

8) a) Classify static relays and explain them.

b) Explain the working of static over current relay.

OR

9) a) Explain amplitude and phase comparators.

b) Explain the scheme of static distance relay.

III YR -EEanucde.info/DEC2014QPS/36-3.pdf5) a) List out the advantages and disadvantages of corona....

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Transcript of III YR -EEanucde.info/DEC2014QPS/36-3.pdf5) a) List out the advantages and disadvantages of corona....