b.tech. degree examination, may - 2013 · pdf fileb.tech. degree examination, may - 2013...

��Total No. of Questions : 9] [Total No. of Pages : 02

B.Tech. DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year Third Semester)

ELECTRICALS AND ELECTRONICS(Paper - I) : Linear Control Systems

Time : 03 Hours Maximum Marks : 75

Q1) a) What is meant by system?

b) Define open loop system.

c) Explain the principles of super position.

d) Define transfer function.

e) What are the time domain specifications?

f) State the characteristics of linear systems.

g) What are the properties and limitations of transfer function of a system?

h) Define poles and zeros.

i) Define peak overshoot.

j) What is delay time?

k) What is settling time?

l) What is stability of a system?

m) List the types of stability.

n) What is impulse function?

o) What is a mathematical model?

UNIT - I

Q2) a) Obtain the transfer function of diagram shown in fig.

b) Distinguish between open loop and closed loop system.

OR

Q3) a) What is a signal flow graph?

b) What are the basic properties of signal flow graph?

c) Write the Maron’s gain formula.

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UNIT - II

Q4) a) Explain transient response of first order and second order systems to standard testsignals.

b) Explain time domain specifications of transient response of a control system.

OR

Q5) Explain Routh hurwitz criterion.

UNIT - III

Q6) a) What are the rules for construction of root locus.

b) Explain nyquist stability criterion.

OR

Q7) What are the various steps in the procedure for constructing root locus?

UNIT - IV

Q8) Explain lead-log compensation techniques based on the frequency response approach.

OR

Q9) a) State the properties of state transition matrix.

b) Explain controllability and observability.

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Electricals and Electronics(Paper - II) : ELECTRONIC CIRCUITS - II


Answer Question No.1 compulsory

Q1) a) What is a feedback? (1)

b) What is loop gain? (1)

c) What is desensitivty? (1)

d) What are the merits and demerits of positive feedback? (2)

e) What is a tank circuit? (1)

f) What are damped oscillations? (1)

g) What are the disadvantages of phase - shift oscillator? (2)

h) What is a heat sink? (1)

i) What is a bistable multivibrator? (1)

j) What is meant by quality factor? (1)

k) What is a double tuned amplifier? (1)

l) What are the advantages of tuned amplifiers? (2)

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

UNIT - I

Q2) a) Explain the performance quantities of a power amplifier.

b) Discuss the temperature considerations in power amplifiers.

OR

Q3) a) Explain the operation of a chopper amplifier.

b) Distinguish between a voltage amplifier and a power amplifier.

UNIT - II

Q4) a) Write the significance of feedback on the amplifier operation.

b) Draw the circuit of a wein bridge oscillator using transistor and explain its operation.

OR

Q5) a) How is stability maintained in feedback amplifiers?

b) Explain the features of a crystal oscillator.

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UNIT - III

Q6) a) Draw a neat diagram and explain the working of a single tuned amplifier.

b) Give the function of a Bistable multivibrator.

OR

Q7) a) Explain the working of a Double Tuned Transformer amplifier with neat diagram.

b) Draw the output waveforms of a schmitt trigger and explain.

UNIT - IV

Q8) a) Design a voltage series regulator and explain its operation.

b) Draw a current sweep circuit and explain its working.

OR

Q9) a) Explain the operation of shunt regulator using discrete components.b) Explain how the deviation from linearity is expressed.

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Electricals and Electronics(Paper - III) : GENERATION OF ELECTRICAL POWER


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

Answer any ONE question from each unit

Q1) a) Define load duration curve.

b) What is the use of economiser?

c) Explain cooling arrangement in Thermal Plant.

d) Define surgetank.

e) Define hydrographs.

f) Define diversity factor.

g) Explain utilization factor.

h) Define solar constant.

i) What is tariff?

j) What is meant by PV cell?

k) What is meant by spining capacity (or) reserve?

l) Define plant use factor.

m) What are the various types of wind blades?

n) Define tidal energy.

o) What are the types of wind generator?

(4 × 15 = 60)

UNIT - I

Q2) a) Explain various sources of power generation methods.

b) What are the conditions to selection site for a thermal station?

OR

Q3) Explain the generation of power at thermal plant with a neat diagram.

UNIT - II

Q4) Classify the various types of hydro-electric plants. Explain briefly.

OR

Q5) Explain the parts of nuclear power plant with a neat diagram.

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UNIT - III

Q6) a) Explain the principle of operation of gas turbine plant.

b) Explain the principle of operation of solar power plant.

OR

Q7) a) Explain the principle of operation wind power plant.

b) Explain the operation of fuel cells.

UNIT - IV

Q8) a) What are the factors affecting cost of generation.

b) What are the reasons for low power factor.

OR

Q9) a) Explain the methods of improving power factor.b) Briefly explain various types of tariff’s.

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ELECTRICALS AND ELECTRONICS(Paper - IV) : Electrical Measurements


Answer Question No.1 compulsory

Answer ONE question from each unit

Q1) a) What is permanent magnet moving coil?

b) Define synchroscope.

c) What is dynamometer?

d) What is operation of frequency meters?

e) What are the bridges to measure inductance?

f) What are the bridges to measure capacitance?

g) What is difference between C.T. and P.T.?

h) What are the causes of errors in instrument transformers?

i) Define transducers.

j) What is meant by permeability?

k) What are the advantages of flux meter?

l) Define strain gauge.

m) What is the principle of thermocouple?

n) Define oscilloscope.

o) Define thermister.

UNIT - I

Q2) a) Explain the permanent magnet moving coil instrument with a neat sketch.

b) What are the advantages and disadvantages of PMMC instruments?

OR

Q3) Explain and classify the moving iron instruments with a neat sketch.

UNIT - II

Q4) Explain the characteristics of current transformer with a neat sketch.

OR

Q5) a) What are the various testing methods of instrument transformers?

b) Describe the working of a capacitive type potential transformer.

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UNIT - III

Q6) a) Describe construction and working of a ballistic galvanometer.

b) Explain the difference in constructional details of a ballistic galvanometer and a‘d’ Arsonval galvanometer.

OR

Q7) Describe the different methods used for calibration of a ballistic galvanometer.

UNIT - IV

Q8) a) Explain the principle of operation of DVM’s.

b) Explain the display devices LEDS, LCDS.

OR

Q9) a) Explain the principle of operation of LVDT.b) Explain the strain gauge with neat sketch.

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ELECTRICALS AND ELECTRONICS(Paper - V) : Transmission and Distribution



Answer any ONE question from each unit

Q1) a) What are the constants of a transmission line?

b) Define mutual inductance.

c) Define skin effect.

d) What is meant by symmetrical spacing?

e) Define voltage regulation.

f) Define surge imedance loading.

g) What is meant by corona?

h) Explain transposition of conductors.

i) List out the advantages of bundled conductors.

j) What is meant by double line circuit?

k) What is meant by circuit breaker?

l) Define isdator.

m) Define insulator.

n) What is meant by insulation resistance in cables.

o) Define string efficiency.(4 × 15 = 60)

UNIT - I

Q2) a) Derive the expressions for inductance and capacitance of single phase system.

b) Explain the effect of ground on capacitance.

OR

Q3) a) Explain the concept of GMR and GMD in the calculations of transmission lineinductance.

b) What are the advantages of bundled conductors?

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UNIT - II

Q4) a) What are the factors affecting corona?

b) A certain 3 - phase equilateral transmission line has a total corona loss of 53 kW at106kV and a loss of 98kw at 110.9kV. What is the disruptive critical voltage? What isthe corona loss at 113kV?

OR

Q5) a) List out the advantages and disadvantages of corona.

b) What are the methods of reducing corona effect?

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

UNIT - III

Q6) a) Explain the connection schemes of distribution system.

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

OR

Q7) a) What are the various types of substations classify and explain briefly?

b) The three busbar conductors in an outdoor substation are supported by units of posttype insulators. Each unit consists of a stack of 3 pin type insulators fixed one on thetop of the other. The voltage across the lowest insulator is 13.1kV and that across thenext unit is 11kV. Find the busbar voltage of the station.

UNIT - IV

Q8) a) What are the methods of equalising 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.

OR

Q9) a) Explain the insulation resistance of a cable.b) A 66kV concentric cable with two inter-sheaths has a core diameter 1.8cm. Dielectric

material 3.5cm thick constitutes the three zones of insulation. Determine the maximumstress in each of the three layers if 20kV is maintained across each of the inner two.

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Total No. of Questions : 9] [Total No. of Pages : 02

B.Tech. (Semester - III) DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year)

ELECTRICALS AND ELECTRONICS(Paper - VI) : ELECTRON MECHANICS - III



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

Q1) a) Write the emf equation of an alternator.

b) What are salient pole rotors?

c) What is the use of potier triangle?

d) State the use of slip test on an alternator.

e) What are the losses that take place in an alternator?

f) Why does synehronous impedance method give a poorer voltage regulation?

g) Which method of regulation is called pessimistic and why?

h) Define breadth factor.

i) What is the role of damper winding in synehronous motor?

j) What is meant by hunting of synchronous motor?

k) What are the advantages of synchronous motor?

l) What is synchronous condenser?

m) Why a 3 - phase synchronous motor will always run at synchronous speed?

n) Give the applications of stepper motor.

o) What are advantages of universal motors.

UNIT - I

Q2) a) Explain the constructional features of an alternator.

b) Derive the emf equation generated in an alternator.

OR

Q3) a) Define the terms synchronous reactance and voltage regulation of alternator. Explainsynchronous impedance method of determining regulation of alternator.

b) Draw and explain the load characteristics of an alternator.

UNIT - II

Q4) a) Discuss Blondel’s two reaction theory applicable to salient pole synchronous machine.

b) Describe the slip test method for the measurement of Xd and X

q of synchronous

machines.OR

Q5) a) Explain what is meant by synchronizing of laternators. What are the various methodsof synchronizing.

b) Explain the factors which affect the sharing of load between two alternators operatingin parallel.

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UNIT - III

Q6) a) Explain effects of varying excitation on armature current and power factor in asynchronous motor. Draw ‘v’ curves.

b) Draw and explain the equivalent circuit of synchronous motor.

OR

Q7) a) Draw and explain the phasor diagrams of a 3 - phase synchronous motor when :

i) It is over excited.

ii) It is under excited.

b) Explain the functions of a damper winding in a synchronous motor.

UNIT - IV

Q8) a) Explain the principle of operation of AC series motors.

b) Write a note on repulsion motors.

OR

Q9) a) Explain the types of 1 - φ synchronous motors.b) Write a note on applications of 1 - φ synchronous motors.

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B.Tech. DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year Fourth Semester)

ELECTRICALS AND ELECTRONICS(Paper - I) : LINEAR IC’s APPLICATIONS




Q1) a) Define CMRR and slewrate. (2)

b) What is voltage follower? Sketch the circuit. (1)

c) Define the input offset current. (1)

d) Draw the filter response of BPF and BSF. (2)

e) Define quality factor of a BPF. (1)

f) What is pass band and stop band for a filter? (2)

g) What is a multivibrator? (1)

h) What is zero crossing detector? (1)

i) What is log amplifier? (1)

j) What is a precision diode? (1)

k) What does the term ‘roll off” mean? (2)

UNIT - I

Q2) a) What are the characteristics of ideal op-amp?

b) Explain the need for compensating network.

OR

Q3) a) Discuss the techniques for minimising offset voltage and current effects.

b) Derive the slew rate equation for an op-amp.

UNIT - II

Q4) a) Explain the working of phase shift oscillator.

b) What are the limitations of op-amps as comparators?

OR

Q5) a) Draw a neat circuit and explain a triangular wave generator.

b) Write short notes on window detector.

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UNIT - III

Q6) a) Explain the working of a R-2R D/A converter.

b) Draw a neat figure explain a peak detector.

OR

Q7) a) How do you obtain Analog to Digital conversion using successive approximationmethod.

b) Explain the features of a positive and negative clippers.

UNIT - IV

Q8) a) Explain the function of a 555 timer as Astable Multivibrator.

b) What is band elimination filter? Draw the frequency response.

OR

Q9) a) What are the advantages of active filter over passive filter?

b) Explain the operating principles of PLL.

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B.Tech. DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year Fourth Semester)

Electrical and Electronics(Paper - II) : MICROPROCESSORS & INTERFACING


Answer Question No.1 compulsory (15)

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

Q1) a) What is the purpose of accumulator? (1)

b) What is a coprocessor? (1)

c) Mention the two main functions of an OS. (2)

d) What is ‘RRC’ instruction? (1)

e) Give example of three-byte instruction. (1)

f) What is an instruction cycle give example? (2)

g) What is instruction prefetching? (1)

h) What is the use of duection flag in 8086? (1)

i) What is implied addressing mode? (1)

j) What are software interrupts? (1)

k) What is NV RAM? (1)

l) What is meant by memory mapping? (2)

UNIT - I

Q2) a) List the features of 8086 microprocessor.

b) Explain relative program memory addressing.

OR

Q3) a) Explain the register organisation of 8086.

b) Explain the use of PUSH and POP instructions.

UNIT - II

Q4) a) Explain how physical address is calculated in 8086?

b) Write a program to convert to 2-digit HEX number to BCD number.

OR

Q5) a) Explain the HOLD response sequence in the minimum mode of 8086 with the help oftiming diagram.

b) Explain various debugger command.

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UNIT - III

Q6) a) Explain the features of DAC 0830.

b) Discuss the software interrupts of 8086.

OR

Q7) a) What is the process of interfacing a microprocessor to keyboards.

b) Explain the features of ADC 0804.

UNIT - IV

Q8) a) Write short notes on Rs.232C.

b) Draw the block diagram of 8259A and explain the function of each block.

OR

Q9) a) Discuss the 8251A control word register.

b) Explain the function of DMA data transfer.

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B.Tech. (Semester-IV) DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year)

ELECTRICALS AND ELECTRONICS(Paper - III) : DIGITAL SIGNAL PROCESSING



Q1) a) What is Discrete time system?

b) What is the importance of impulse response?

c) Define transfer function of a system.

d) What are the Dirchlet’s conditions for Fourier series?

e) What are the applications of Digital Signal Processing?

f) What are the limitations of Energy and Power signals?

g) When the signal is said to be Periodic?

h) What is Time Invariant System?

i) Draw the spectrum for Discrete Fourier transform of signum function?

j) Express in mathematically Fourier transform of convolution.

k) What is meant by Twiddle factor?

l) Write the expression for cross correlation of periodic signals?

m) What is ROC of Z-Transform?

n) State the different types of filters based on frequency response?

o) What is the necessity of Window?


UNIT - I

Q2) a) Determine the impulse response of the system described by the difference equationy (n) –3y (n –1) –4y (n–2) = x (n) + 2x (n – 1) using Z-transform?

b) Explain magnitude and phase spectrum with reference to frequency response of system?

OR

Q3) a) Prove that impulse response of an LTI system is absolutely summable for stability ofthe system?

b) Check the following systems for linearity, causalty, time invariance and stability.

i) y (n) = ne|x (n)|.ii) y (n) = ancos (2pn/N)?

UNIT - II

Q4) a) Compute the N-point DFT of each of the following sequences.

i) x1 (n) = δ (n – n

0) where 0 < n

0 < N

ii) x2 (n) = an where 0 < n < N?

b) What is the computational efficiency of FFT Radix-2 DIT Algorithm for an N-pointsequence? Compare it with that of Direct DFT computation?

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OR

Q5) a) Define DFT of a sequence. Compute the N-point DFT of the sequence X (n) = cos(2πn/N) where 0 < n < N-1 and 0 < r < N-1?

b) Evaluate the 8-point DFT for the following sequence using DIT-FET algorithm x (n)= {1,1,1,1,1,1,1,1}. Also sketch magnitude and phase responsess?

UNIT - III

Q6) a) Determine the system function H (z) of the lowest order chebyshev digital filter thatmeets the following specifications.

i) 1db ripple in the pass band 0 < |w| < 0.3π.ii) At least 60db attenuation in the stop band 0.35π < |w| < p. Use the Billnear

transformation?

b) Convert the Analog Transfer function )2(31)(3

1H(S)

′++= find H(z) using impulse

invariant method, also check stability of this filter. Assume T = 1 sec?

OR

Q7) a) Find H(z) using impulse Invariant Method for given Analog System

2)z5.02

(z)5.0(3

1H(S)

+++=

b) Design a High Pass filter using Butterworth approximation for the given specificationsaα = 3dB, a

s = 15db, Ωα = 1000rad/sec?

UNIT - IV

Q8) a) Design an low pass FIR filter using Rectangular window with pass band gain ofunity, cut-off frequency of 1000 Hz and sampling frequency of 5kHz. Assume thelength of the impulse response as 7?

b) Explain the Designing of FIR filter using Kaiser window. What are the advantages ofthis method?

OR

Q9) a) Design a low pass FIR filter with a Rectangular window for a five stage filter givensampling time 1msec, f

c = 200Hz. Draw the filter structure with minimum number of

multipliers?

b) Find Direct form - I and Direct form - II realizations for the second-order filter givenby Y (n) = 2bcosω

0y (n – 1) – b2 y (n – 2) + x (n) – bcosω

0 x (n – 1).

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B.Tech. (Semester - IV) DEGREE EXAMINATION, MAY - 2013(Examination at the end of Third Year)

ELECTRICALS AND ELECTRONICS(Paper - IV) : POWER ELECTRONICS



Q1) a) What is IGBT?

b) Draw snubber circuit for a SCR.

c) What are conduction losses?

d) Draw the equivalent model of DIAC.

e) Distinguish between a converter and Inverter.

f) What is the significance of source Inductance?

g) Define extinetion angle.

h) Explain the need for firing pulses in Power Electronics.

i) What is natural commutation?

j) Draw the circuit of dual converter.

k) List the different types of commutation techniques.

l) Name the various digital firing schemes.

m) Give the applications of cycloconverters.

n) What are the advantages of PWM technique?

o) List the different classes of choppers.


UNIT - I

Q2) a) Explain in detail the two-transistor model of SCR.

b) Discuss about the series operation of SCR.

OR

Q3) a) What are the different turn-on method employed in SCR? Explain them briefly.

b) What is a MOSFET. Explain its V-I characteristics briefly. Also write its advantagesover other switches.

UNIT - II

Q4) a) Explain with waveforms and equations, the operation of single-phase full convertersfed with RL load.

b) Discuss the PWM contral used for power factor improvement.

OR

Q5) a) Briefly explain the operation of single-phase dual converter.

b) Write a note on the effect of bad inductance in converters.

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UNIT - III

Q6) a) Explain the operation of single phase parallel inverter.

b) Write a note on current source inverters.

OR

Q7) a) Explain the operation of three-phase inverters for 120º mode of operation with relevantwaveforms.

b) Discuss briefly various PWM techniques used in inverter circuits.

UNIT - IV

Q8) a) Explain the basic principle of chopper. Derive the output voltage expression for anyone chopper circuit.

b) Discuss the role of choppers in the speed control of DC motors.

OR

Q9) Explain in detail the principle of operation of single-phase cycloconverters.

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ELECTRICALS AND ELECTRONICS(Paper - V) : UTILIZATION OF ELECTRICAL POWER




Q1) a) Define plane Angle.

b) Define solid Angle.

c) What is meant by Lumen?

d) What is meant by luminous intensity?

e) What is illumination?

f) Define polar curves.

g) What is meant by load equalization?

h) Define crest speed.

i) Define welding.

j) Define electric drive.

k) What is cooling of motor?

l) Define plugging.

m) Define stefan’s law.

n) What is meant by duty cycle?

o) Define torque.

UNIT - I

Q2) a) What are the advantages of electric drive?

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

OR

Q3) a) Comparision between A.C. drive and D.C. drive.

b) A 10kw motor has a temperature rise of 40ºC while working continuously on full-load for ‘t’ hours. It has a heating time constant of 100 minute and final steadytemperature is 50ºC. Find the value of t.

UNIT - II

Q4) a) What are the advantages of electric fraction.

b) What are the disadvantages of electrictraction.

OR

Q5) a) Explain the speed-time curve of traction.

b) Factors affecting the schedule speed.

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UNIT - III

Q6) a) What are the advantages of electric heating?

b) What are the requirements of good heating element.

OR

Q7) a) Derive the expression for design of heating element.

b) What should be the rating of heating element to be placed in a 300 litre water tank inorder to raise the temperature of water from 15ºC to 80ºC in 3 hrs? Assume

i) Heat loss is negligible.ii) Heat loss is 2 × 106 J/hr.

UNIT - IV

Q8) a) Derive the relation between phase angle and solid angle.

b) What are the requirements of good lightning.

OR

Q9) a) Explain the laws of illumination.

b) A lamp is taking a current of 0.6A at 230V and 125MHCP. Find its efficiency inMHCP per watt and lumen per watt if spherical reduction factor is 0.77

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ELECTRICALS AND ELECTRONICS(Paper - VI) : SWITCH GEAR & PROTECTION



Q1) a) Define Relay.

b) What is meant by backup protection?

c) What is meant by recovery voltage?

d) Explain the need for protective relays.

e) Define plug setting multiplier.

f) Define current chopping.

g) What is meant by neutral grounding?

h) Define earth resistance.

i) Explain soil resistivity.

j) What is meant by breaking capacity?

k) Define amplitude comparators.

l) What is meant by percentage ratio error?

m) Define setting value.

n) Define reach.

o) Define the term burden.


UNIT - I

Q2) a) What are the various protective schemes in switch gear and protection.

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

OR

Q3) Explain briefly electronmechanical relays with a neat sketch.

UNIT - II

Q4) a) Explain SF6 circuit breaker with a neat sketch.

b) What are the elementary principles of arc phenomenon?

OR

Q5) a) Explain vaccum circuit breaker with a neat sketch.

b) Explain the specifications of a circuit breaker.

UNIT - III

Q6) a) With a neat diagram explain differential protection for generators.

b) Explain Translay relay with neat sketch.

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OR

Q7) a) What are the objectives of earthing?

b) Explain the solid granding with neat sketch.

UNIT - IV

Q8) a) What are the merits and demerits of static relays?

b) Compare between electromechanical relays and static relays.

OR

Q9) a) What are the different types of differential relays?

b) Explain inverse time over current relays.

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b.tech. degree examination, may - 2013 · pdf fileb.tech. degree examination, may - 2013...

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