(DEE 211) - Anucdeanucde.info/DEC11QPS/36-BTEE2.pdf · 2012-02-12 · (15 1 = 15) Answer ONE...

(DEE 211) B.Tech. DEGREE EXAMINATION, DECEMBER 2011.

(Examination at the end of Second Year)

Electricals and Electronics Engineering

Paper I — MATHEMATICS — III

Time : Three hours Maximum : 75 marks

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

Answer ONE question from each Unit.

(4 15 = 60)

1. (a) If xxxf cos)( in ),( find 1b .

(b) Find the half range sine series for 1)( xf in ),0( .

(c) State Fourier integral theorem.

(d) Write the Fourier cosine integral formula.

(e) State modulation theorem for Fourier transforms.

(f) Find Fourier transform of 2

2x

e

.

(g) States that convolution theorem for Fourier Transform.

(h) Explain algebraic equation. Give an example.

(DEE 211) 2

(i) Write the regular falsi method formula,.

(j) Evaluate

21

21

EE 21

)1( .

(k) Evaluate ).(log xf

(l) State Trapezoidal rule.

(m) Given that

x : 1 2 3

f (x) : 3 8 15

Find )1(2f .

(n) Write the Gauss's stirling's formula.

(o) Write the third-order Runge-Kutta method formula.

UNIT I

2. (a) Find a fourier series to represent 2)( xxf on the interval [0, 2 ].

(b) Find the half range sine series for xxxxf 0),()( . Deduce that

32...

71

51

31

11 3

3333

.

Or

(DEE 211) 3

3. (a) Expand xexf )( as a Fourier series in

)1,1( .

(b) Using Parseval's identity , show that

0

2222 ))(( bxaxdx

= )(2 baab

.

UNIT II

4. (a) Find the Fourier transform of )(xf defined

by

1||if,01|| if,1

)(2

xxx

xf . Hence evaluate

3

sincosx

xxx.

2cos dx

x

(b) Find the fourier sine transform of

..5.2 25 xx ee

Or

5. (a) Find a real root of 2. xex using Regular-

Falsi method.

(b) Find a real root of xex using Newton-Raphson method.

UNIT III 6. (a) Using Gauss forward interpolation formula.

To find )30(f . Given that )21(f = 18.4708, 8144.17)25( f , )29(f = 17.1070,

)33(f = 16.3432, 5154.15)37( f .

(DEE 211) 4

(b) Find the interpolation polynomial for the following :

x 0 1 2 5 y 2 3 12 147

Or 7. (a) From the following table of x and y obtain

dxdy

and 2

2

dxyd

for 5.1x .

x 1.5 2.0 2.5 3.0 3.5 4.0 y 3.375 7.0 13.625 24.0 38.875 59.0

(b) Compute )4('f from the following table

x 1 2 4 8 10 f (x) 0 1 5 21 27

Using Newton's divided difference formula. UNIT IV

8. (a) Evaluate 2

1

dxxex

using Simpson's 31

rule

Trapezoidal rule for n = 4.

(b) Given that 1)0(,1 yxydxdy

. Compute

y (0.1) and y (0.2) using Picards method. Or

9. Solve the D.e. 1)0(,2 yyxdxdy

by modified

Euler's method. Find y (0.02), y (0.04).

—————

(DEE 212)

B.Tech. DEGREE EXAMINATION, DECEMBER 2011.



Paper II — NETWORK ANALYSIS – I


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

Answer ONE question from each Unit. (4 15 = 60)

1. Answer the following

(a) Define passive element.

(b) Define dependent sources.

(c) Write the relationship between charge and energy.

(d) Explain the kirchhoff's voltage law.

(e) State the Tellegan's theorem.

(f) State the Millman's theorem.

(g) Define west factor.

(h) Define form factor.

(i) Define power factor.

(j) What is -factor?

(k) State the initial value theorem.

(l) Define time constant of an RL circuit.

(m) Define Reactive power.

(n) Define Resonance.

(o) Define Bandwidth.

UNIT I

2. (a) Reduce the network of fig into a single resistance between A and B.

(DEE 212) 2

(b) Find the magnitude of current in 10 resistor in the network of fig.

Or

3. (a) Explain the Nodal analysis.

(b) Find the current through 4 resistor in the circuit of fig by nodal method.

UNIT II

4. (a) State and explain super position theorem.

(b) Find the current in 4 resistor in the circuit shown in fig, using thevenin's theorem.

Or

5. (a) Find the Rms and average value of full-rectified sinusoidal current waveform. Hence

find form factor and amplitude factor.

(b) A resistor R is connector in series with a capacitor C and the combination is connected

across a 100 V, 50 Hz supply. The voltage drop across the resistor is 60 V and the power

dissipated in the resistor is 108 w. Find R and C.

(DEE 212) 3

UNIT III

6. An RLC series circuit has R = 20 , L = 0.3 H and C = 0.1 mF, connected across a 200 V, 50 Hz supply. Find

(a) Reactance

(b) Impedance

(c) Current

(d) Phase angle

(e) Power factor

(f) Voltage across R, L, C.

Or

7. (a) Obtain the current locus of an R-L series circuit.

(b) For a two branch parallel circuit RL = 6 , RC = 9 , XL = 12 . Find the two values of L and the two values of total current at resonance when connected to a 100 V, 50 Hz supply.

UNIT IV

8. (a) State and prove find value theorem.

(b) Write short notes on saturating exponential function.

Or

9. (a) Narrate the importance features of PSPICE.

(b) Explain the description of circuit elements.

–––––––––––

(DEE 213)



Electricals and Electronics

Paper III — ELECTRONIC DEVICES


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

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

1. (a) Define vertical sensitivity of CRT?

(b) What is a diffusion current?

(c) What is the mobility of charged particle?

(d) Define magnetic Deflection.

(e) State the advantages of LCD.

(f) What is entimsic semiconductor?

(g) What is zener break down?

(h) Drew the photodiode control circuit?

(i) If the value of = 0.973, what is the value of ?

(j) What is early effect?

(DEE 213) 2

(k) What do you under stand by Q–Point?

(l) Why MOSFETs are metered over BJTS in VLSI design?

(m) Give Applications of SCR?

(n) Differentiate between TRIAC and DIAC?

(o) Write the relation between , gm?

UNIT I

2. (a) Draw the basic structure of a CRT and identify different components?

(b) State and explain law of mass actions.

Or

3. (a) Derive continuity equation and state its special cases?

(b) Compare electrostatic and magnetic deflection?

UNIT II

4. (a) Explain the term transition capacitance CT of p–n junction diode? Derive an expression for it.

(b) Explain the characteristics of verector diode with help of diagram.

Or

5. (a) Draw the V–I characteristics of zener diode?

(b) Explain the characteristics of a photodiode?

(DEE 213) 3

UNIT III

6. (a) Explain the Input and output characteristics of a transistor in CB configuration?

(b) Explain different techniques used for biasing transistor amplifier

Or

7. (a) How to obtain bias stability in CE configuration circuit?

(b) Prove that for a CE transistor in a active region .)1( IcoII BC

UNIT IV

8. (a) Explain how FOT can be used as switch?

(b) Explain two transistor analogy of SCR?

Or

9. (a) Explain how UJT can be used as relaxidion oscillator?

(b) Explain the operation TRDAC?

——————

(DEE 214)


Second Year


Paper IV – ELECTRICAL AND ELECTRONICS ENGINEERING MATERIALS


Answer Question No. 1 compulsorily. (15 1 = 15)


1. (a) Mention few applications of nano structured materials.

(b) State Wiedemann – Franz law.

(c) Define electrical conductivity.

(d) Define drift velocity of electrons.

(e) What is Meissner effect?

(f) What is isotope effect in super conductivity?

(g) What are high temperature super conductors?

(h) What is meaning of penetration depth?

(i) Give few examples of dielectric materials.

(DEE 214) 2

(j) What are the characteristics of nanotubes?

(k) Define energy product of a magnetic material.

(l) What are dielectrics?

(m) What is electric polarization?

(n) Explain the term dielectric loss.

(o) Define piezo electricity.

UNIT I

2. Write short notes on the following :

(a) nano wires

(b) tubes

(c) carbon nano tubes.

Or

3. (a) Explain the electrical characteristics of carbon nano tubes.

(b) Explain the applications of nano-structured materials.

UNIT II

4. Explain the mechanism of intrinsic conduction in semi conductors. Derive an expression for conductivity of an intrinsic semiconductor in terms of carrier concentration and carrier mobility.

Or

(DEE 214) 3

5. Distinguish between direct and indirect based gap in semiconductor describe a method of determining the band gap of a semiconductor. How does the electrical conductivity vary with temperature for an intrinsic semiconductor?

UNIT III

6. (a) Distinguish type I and type II superconductors. Write a note on high Tc super conductors.

(b) Write an essay on superconducting materials and its applications. What are the new developments.

Or


(a) Londou's equation

(b) BCS theory and copper pairs.

UNIT IV

8. (a) Explain the classification of dielectrics.

(b) Write short notes on electric polarization and polarisability.

Or

9. (a) Explain the clausius – Mossotti relation.

(b) Explain the types of dielectric breakdown.

————————

(DEE 215)




Paper V — DIGITAL ELECTRONICS


Answer question No. 1 compulsorily.

(15)


(4 15 = 60)

1. (a) Convert the given binary number in to grey codes 10010011101.

(b) Convert the hexa decimal number F3A7C2 to binary and octal.

(c) Determine the value of base x if

8)152()211( x .

(d) Write a Boolean expression for two input NOR gate.

(e) A POS expression leads to what kind of logic circuit.

(DEE 215) 2

(f) What is an encoder?

(g) Realize full substractors using half substractors.

(h) What is a flip flop?

(i) What do you understand by race around condition?

(j) Draw the excitation table of Rs. flip flop.

(k) What is the difference between synchronous and asynchronous sequencial circuits?

(l) Why should TTL gate in puts never be left floating?

(m) What is the transfer characteristic of a CMOS inverter?

UNIT I

2. (a) Simplify the Boolean function by using K-map )14,13,12,9,8,6,5,4,2,1,0()( ABCDf .

(b) Simplify the expressions in

(i) SOP

(ii) POS

(1) xyyzzyyx 11111

(2) )()( CBADBA )( DBA )( DCB .

Or

(DEE 215) 3

3. (a) Determine the prime implicates of the function )15,11,10,9,8,7,6,4,1(),,,( zyxwf .

(b) Simplify

(i) zxwyxxzzw

(ii) CABCBACBADB .

UNIT II

4. (a) Explain carry look-ahead adder.

(b) Implement the given boolean function with an 8 1 multiplexer.

)15,14,9,8,6,5,3,0()( ABCDF .

Or

5. (a) Design a BCD – to seven segment decoder.

(b) Construct a 16 1 MUX with two 8 1MUX and one 2 1 MUX.

UNIT III

6. (a) Explain the operation of master-slove TK flip flop.

(b) Convert a given TK flipflop to D flipflop.

Or

(DEE 215) 4

7. (a) Draw the logic diagram of master stack D flip flop by using NAND gets and explain its working.

(b) Design a 4-bit binary synchronous counter with D-Flipflops.

UNIT IV

8. (a) Draw the circuit of TTL NAND gate and explain.

(b) A combinational circuit is defined by the functions

)7,6,5,3(),,(1 zyxF

)7,4,2,0(),,(2 zyxF .

Implement the circuit with PLA.

Or

9. (a) Write a short notes on PLDS.

(b) Explain briefly about CMOS inverter.

——————

(DEE 216) B.Tech. DEGREE EXAMINATION, DECEMBER 2011.



Paper VI — ELECTRO MECHANICS — I




(4 15 = 60)

1. (a) Define mechanical energy.

(b) What is electric field energy?

(c) Explain energy conversions.

(d) Explain armature reaction.

(e) What is the maximum efficiency in DC generator?

(f) What is lap winding?

(g) What are the losses in a DC generator?

(h) Give applications of OC series generator.

(DEE 216) 2

(i) Give applications of DC compound motor.

(j) Draw the circuit diagram in a DC shunt generator.

(k) Write voltage equation in a DC generator.

(l) What is the function of commutator?

(m) What is the function of 3 point stark?

(n) What are the advantages of Swinburne's test?

(o) What are the limitations of field test.

UNIT I

2. (a) Explain the field energy and mechanical force.

(b) Write short notes on energy conversion through electric fields.

Or

3. (a) Explain the Torques in systems with permanent magnets.

(b) Explain energy balance.

(DEE 216) 3

UNIT II

4. Draw a neat sketch of a DC machine and label the component parts. Name the material used for each component part.

Or

5. (a) Explain the function of a commutator in a DC machine for motoring and generating action.

(b) With the help of simple examples explain the difference between lap winding and wave winding.

UNIT III

6. Draw and explain torque-speed characteristics for the following types of dc motor (a) shunt motor (b) series motor (c) compound motor.

Or

7. (a) Deduce the equation for speed of a dc motor and hence suggest various methods of speed control.

(b) A 230 V dc shunt motor takes an armature current of 20 A on a particular load. The armature circuit resistance is 0.5 . Find the resistance required in series with the armature to reduce the speed by 50% of (i) the load torque is constant and (ii) the load torque is proportional to the square of the speed.

(DEE 216) 4

UNIT IV

8. Write a short notes on principle and working of amplitude and metadyne.

Or

9. Explain Hopkinson's test in detail.

————————

(DEE 217)




Paper VII — ENVIRONMENTAL STUDIES




1. Explain the following in 1 or 2 sentences :

(a) Define the term ‘desert’.

(b) What are the types of echosystems?

(c) What is soil erosion?

(d) What is desertification?

(e) What are the various non renewable energy

sources?

(DEE 217) 2

(f) What is Acid rain?

(g) What are the various pollutions?

(h) What are the sources of air pollution?

(i) Define global warming.

(j) What are the effects of marine pollution?

(k) What is cloud seeding?

(l) What are the measures used for control of

soil pollution?

(m) What is Natality?

(n) Define population density.

(o) What is the use of life tebed?

UNIT I

2. Explain the importance of Lakes, Rivers and

Estuaries.

Or

3. Explain in detail about the forest resources.

(DEE 217) 3

UNIT II

4. Define biodiversity. Explain the importance of biodiversity.

Or

5. Define pollution and pollutant. Name the sources of air pollution in big cities. What type of pollutants do they produce?

UNIT III

6. Explain in detail about watershed management.

Or

7. Explain briefly about the strategies for sustainable development.

UNIT IV

8. Explain the salient features of following acts :

(a) Forest conservation act

(b) Coastal core regulations.

Or

(DEE 217) 4

9. Write short notes on :

(a) Water Act

(b) Air Act.

–––––––––––

(DEE 221)




Paper I — MATHEMATICS – IV




(4 15 = 60)

1. (a) Cauchy–Riemann equations for a function to the analytic in polar form are.

(b) The value of K so that 22 2 kyxx may be harmonic is

(c) A point at which tf fails to be analytic is called.

(d) The harmonic Conjugate of yex cos is

(e) If yxivyxutf ,, be analytic an and within a simple closed curve c and tf is

continuous, then c

dttf is

(f) State Cauchy’s Integral formula.

(DEE 221) 2

(g) Write the poles of the function t

ttf

cos

(h) Find residue of rr

r

tatt

tf at ait

(i) Expand ttf 1log in a Taylor’s series about 0t .

(j) Generation function for xJn is

(k) Write the value of xJn interms of xJn is

(l) Define Bessel’s function (m) What is the value of 1nP

(n) Find the value of dxxPx nm

1

1

(m being

antiteger <n) (o) The Legendre polynomial xPn has n real

teros between – and –. UNIT I

2. (a) Determine P such that the function

ypx

Tanyxtf rrr log21

be an analytic

function. (b) If yxu , and yxv , are harmonic functions

in a region R, P.T. the function

yv

xu

xv

yu is an analytic

function. Or

(DEE 221) 3

3. (a) Find the analytic function whose real part is

(i) rr yxx

(ii) rr yxy

.

(b) Find the Conjugate harmonic function of the harmonic function 22 yxu .

UNIT II

4. (a) Evaluate c

rvr

t

dtt

e

where c is 4t .

(b) Evaluate

cr

t

dtit

tte 4

3 where 2: tC by

using Cauchy’s Integral formula. Or

5. (a) Obtain the Taylor’s series expansion of

1

tte

tft

about 2t .

(b) Expand tlog by Taylor’s series about 1t .

UNIT III 6. (a) Find the Residue of the following

(i) 11

222

2

tt

tt

(ii) tTan at each pole.

(b) Find the poles and residues of each pole of

3

coth.cost

tt.

Or

(DEE 221) 4

7. (a) Show by the method of Residues

0cos 22

ba

babad

o

(b) Solve in series the differential equation

.0232

2

ydxdy

dxyd

x

UNIT IV

8. (a) P.T. (i) xx

xJ sin2

21

(ii) x

xJxJ22

212

21

(b) P.T. xJxJxxJxJxdxd

nnnn2

12

1. .

Or

9. (a) Using Rodrigue’s formula P.T.

1

1

0dxxPx nm if nm .

(b) Using the generating function P.T. 0012 nP .

———————–––

(DEE 222)



Electronicals and Electronics

Paper II — Electronics Circuits – I




1. (a) What are the disadvantages of half wave rectifiers?

(b) Why choke input filters are not in use, now a days?

(c) What is the difference between clipping and clamping?

(d) What is meant by ramp input?

(e) List the benefits of h-parameters.

(f) Draw the frequency response of amplifier.

(g) State Miller's theorem.

(h) Why darlington connections cannot be used for mole no.of stages?

(i) What is the effect of cascading on bandwidth?

(j) Give the significance of two capacitors in hybrid- model.

(k) Give the expression of gain bandwidth product for voltage.

(l) Define cutoff frequency.

(m) What is diffusion current?

(n) What are the guide lines for analysis of transistor?

(o) What is the relation between fT and f?

UNIT I

2. (a) Draw the circuit diagram of draft wave rectifier and explain its operation with the help of wave forms.

(b) Explain the types and applications of clipper circuits. How we can analyse the clipper circuits?

Or

(DEE 222) 2

3. (a) Obtain the RC low pass filter response for ramp input.

(b) Derive the expression for ripple factor of half wave and full wave rectifier.

UNIT II

4. (a) Explain the small signal analysis of single stage CE amplifier.

(b) State and prove Milter's theorem.

Or

5. (a) Hybrid equivalent circuit of CE configuration G shown in fig?

Calculate :

(i) Voltage gain

(ii) Current gain

(iii) Input impedance

(iv) Output impedance.

(b) What is Darlington connection? Explain the advantages of it.

UNIT III

6. (a) Derive the expression for CE short circuit current gain AP as function of frequency.

(b) A transistor short circuit current gain is measured to be 25 at frequency of 2 MHz. If

the transistors f = 200 kHz. Determine

(i) Current gain bandwidth product

(ii) Hole at law frequency

(iii) Short circuit current gain at 10 MHz 2 100 MHz.

Or

7. (a) What are different capacitances of hybrid- model? Derive the expression fd its.

(b) Explain the significance of all resistive components of hybrid- model.

(DEE 222) 3

UNIT IV

8. (a) Draw and explain small signal low frequency model for JFET.

(b) Derive the expression for Ai, Ri, Av, Ro of boot strapped Darlington circuit.

Or

9. (a) Draw and explain the block diagram of two-stage cascade amplifier.

(b) For a CG amplifier if R1 = 3.5 M, R2 = 1.1 M, RD = 3.8 , RS = 3.5 k,

RL = 80 k fit parameters are gm = 5000 s, rd = 65 k calculate input impedance,

output impedance and voltage gain.

–––––––––––

(DEE 223)




Paper III — ELECTROMAGNETIC FIELD THEORY


Answer Question No. 1 Compulsorily. (15 1 = 15)


1. (a) State coulomb's law in electrostatics.

(b) Give the limitations of Gauss's law.

(c) Explain the term Electric field intensity.

(d) Explain the term Electric potential.

(e) State any two methods of producing magnetic field.

(f) Define permeability.

(g) What are the relation between magnetic flux and magnetic flux density and magnetic field intensity.

(h) Define solenoid.

(i) State ampere's current law.

(DEE 223) 2

(j) What is skin effect?

(k) Explain displacement current.

(l) Write the expression of faraday's law in integral form.

(m) Explain the poynting vector.

(n) Explain Biot-savart law

(o) For stationary currenet fields, what is the value of J. ?

UNIT I

2. (a) Find the expression for the electric field intensity due to a line charge.

(b) Derive the relation between electric field and electric potential in rectangular co-ordinates.

Or

3. (a) Obtain the general solution for the potential distribution using cylindrical to ordinates solution of laplace's equations.

(b) In cylindrical coordinates, V=60V at p 6 mm and V=0 at p 66 mm. Find the voltage at p 140 mm, if the potential depends only on p.

(DEE 223) 3

UNIT II

4. (a) Derive the expression for mutual inductance m.

(b) A solenoid with 300 turns in 300 mm long and 30mm is diameter. If the current is 500mA. Find (i) inductance (ii) energy stored is solenoid, Assume 1rM

Or

5. (a) Determine the mutual inductance between an infinitely long straight conductor along y -axis a rectangular single-turn coil situated in X-Y plane with its corners located at points (a,o) (a+d,o) (a,h) and (a+d,h)

(b) Evaluate the inductance of a solenoid of 2800 turns wound uniformly are a length 0.6 cm on a cylindrical paper tube 4cm in diameter. The medium is air.

UNIT III

6. (a) Explain faraday's law of electromagnetic induction and derive the expression for induction E.M.F.

(b) Derive the expression for one of the

Maxwell's equation tB

E

)*( .

Or

(DEE 223) 4

7. (a) Write and explain differential and integral forms of Maxwell's equations.

(b) Derive expression for energy stored in negative field in terms of vector potential.

UNIT IV

8. (a) Derive an expression for wave equation in free space.

(b) Explain the power flow and power density in an electromagnetic field.

Or

9. (a) State and explain poynting theorem.

(b) Derive an expression for power density in perfect dielectric electromagnetic field.

———————

(DEE 224)




Paper IV — NETWORK ANALYSIS — II

Time : Three hours Maximum : 75 marks Answer Question No. 1 is compulsory.

(15 1 = 15) Answer ONE question from each Unit.

(4 15 = 60)

1. (a) Define oriented graph.

(b) What is non planar circuit?

(c) Define tree.

(d) Define co-tree.

(e) Define duality networks.

(f) Write down the properties of path of a graph.

(g) Define a two-port network.

(h) State the application of hybrid parameters.

(i) Define mutual inductance.

(j) What is coefficient of coupling?

(k) Explain the dot convention.

(l) Define constant K filter.

(m) What is meant by dual of network?

(n) State Millman's method.

(o) What is the power factor of 3y system?

(DEE 224) 2

UNIT I

2. (a) Draw the graph of the network whose reduced incidence matrix is given below : 1 2 3 4 5 6

1 0 1 –1 0 0 0 2 1 –1 0 1 0 0 3 0 0 0 –1 1 0 4 –1 0 0 0 –1 –1

(b) For the network shown in Fig. develop the fundamental cut-set matrix and write KCL equations.

Or


(a) Open circuit impedance

(b) Short circuit admittance

(c) Transmission parameters.

UNIT II


(a) Ladder and Lattice networks

(b) Network functions for the two-port bridged-T.

Or

5. (a) Obtain the impulse response of RLC circuit.

(b) In the circuit shown in fig., find the transient current after the switch is closed at t = 0, an initial charge of 100 MC is stored in the capacitor as shown :

UNIT III

6. (a) An air cored solenoid of 1 m in length and 8 cm is diameter has 4000 turns. Calculate (i) the inductance (ii) the energy stored in the magnetic field when a current of 1 A flows in the solenoid.

(b) A coil consists of 1000 turns. A current of 10 A in the coil gives rise to a magnetic flux of 1500 MWb. Calculate (i) the e.m.f. induced (ii) the energy stored when the current is reversed in 0.01 sec.

Or

(DEE 224) 3

7. (a) Briefly discuss the constant m-filters.

(b) Design a m-derived pass filter having a design impedance of 200 n, cut off frequency of 1000 Hz and m = 0.5. Find the frequency of infinite attenuation.

UNIT IV

8. (a) Briefly discuss about the analysis of 3 phase balanced circuits.

(b) A balanced star connected load is connected to a balanced 3 phase 400 V system. Two wattmeters are connected to measure the total power and they read 1000 W and 2000 W respectively. Describe the load impedance per phase.

Or

9. (a) Explain the star/delta transformation method.

(b) The power measured in a 3 phase circuit is made by using two wattmeters and their readings are

(i) 1w = 1.5 kW and 2w = 2 kW

(ii) 2w kW and 2w = 2 kW after the reversal of current coil connections. Determine the power and power factor.

—————————

(DEE 225)




Paper V — PRIME MOVERS AND PUMPS




1. (a) Define mass density.

(b) Define Relative density.

(c) What are the properties of fluids?

(d) What are the various efficiencies of centrifugal pumps?

(e) What are the different types of casings of centrifugal pumps?

(f) What are the different types of turbines?

(g) What is cavitation?

(h) What is the purpose of the draft tube in turbines?

(DEE 225) 2

(i) List out important components of a carnot

cycle.

(j) List out important components of a diesel

cycle.

(k) What is velocity diagram?

(l) Draw the P-V diagrams of otto-cycle.

(m) What is Quasi-static process?

(n) Define Impulse turbine.

(o) Define Enthalpy and what are its units.

UNIT I

2. A jet of water of 30 mm diameter strikes a hinged

square plate at its centre with a velocity of

20 m/sec. The plate is deflected through an angle

of 20. Find the weight of the plate.

Or

3. (a) What is priming? Why is it necessary?

(b) Define a centrifugal pump. Explain the

working of a single-stage centrifugal pump

with sketches.

(DEE 225) 3

UNIT II

4. (a) What is meant by the speed ratio of a pelton wheel?

(b) A peton turbine develops 3000 KW under a head of 300 m. The overall efficiency of the turbine is 83%. If speed ratio = 0.46, Cv = 0.98 and specific speed is 16.5, then find

(i) Diameter of the turbine

(ii) Diameter of the jet.

Or

5. (a) What is draft tube? What are its functions?

(b) A turbine is to operate under a head of 25 m at 200 r.p.m. The discharge is 9 cumec the efficiency is 90%, determine the performance of the turbine under a head of 20 meters.

UNIT III

6. (a) Prove that work is a path function.

(b) Air at a pressure of 50 bar and a volume of 0.2 m3 is expanded at constant pressure until the volume is doubled. It is then expanded according to Pv1.3 = constant, until the volume is 0.8 m3 calculate the work done in each process.

Or

7. Derive the equation for finding efficiency of Rankine cycle.

(DEE 225) 4

UNIT IV

8. Explain with neat sketch working of 2-stroke and 4-stroke engines.

Or

9. Draw the combined velocity triangles of an Impulse steam turbine and derive its equation for finding maximum efficiency.

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(DEE 226)




Paper VI — ELECTRO MECHANICS — II




1. Write briefly on the following :

(a) Explain the principle of working of a transformer.

(b) Define form factor.

(c) Write the emf equation of a transformer.

(d) Define regulation.

(e) Define all day efficiency.

(f) On which side of the transformer, the SC test is conducted? Why?

(g) Explain tertiary transformer winding.

(h) Explain load sharing of a transformer.

(i) What are the types of starters?

(DEE 226) 2

(j) Why tap changing are provided in transformer?

(k) Explain the principle of operation of a induction motor.

(l) Write any two types of cooling systems provided in a transformer.

(m) Define crawling.

(n) Give the applications of shaded pole motor.

(o) What is starting torque?

UNIT I

2. (a) Explain mutual flux, leakage flux, magnetising reactance and leakage reactance of a transformer.

(b) Draw the no-load phasor diagram of a transformer. Express the magnetising current and loss component of the no-load current interms of the no load current and no load power factor.

Or

3. Draw the equivalent circuit of a transformer with (a) primary quantities referred to the secondary side, and (b) secondary quantities to the primary side.

(DEE 226) 3

UNIT II

4. (a) Explain the parallel operation and loading sharing in transformer.

(b) Make a comparison in the weight of copper required in an autotransformer and a two-winding transformer of the same rating.

Or

5. (a) Explain the Scott connection of transformer.

(b) Two transformers are connected in parallel to supply a common load of 125 KKV at 0.8 pf lagging. Rating of transformer A is 100 KVA and has resistance and reactance of 0.9% and 10% respectively. Rating of transformer B is 50 KVA and has resistance and reactance of 1.0% and 5% respectively. How will the two transformers share the common load?

UNIT III

6. (a) Describe the differences in construction between a slip ring induction motor and a squirrel-cage induction motor.

(b) Write the equation for torque of a polyphase induction motor at any value of slip defining all the terms.

Or

(DEE 226) 4

7. What tests are to be performed on an induction motor to be able to draw its circle diagram? What are information one can get about the performance of the motor from the circle diagram? What assumptions are made in drawing the circle diagram.

UNIT IV

8. Explain the working of principle of a single-phase induction motor with the help of double revolving field theory.

Or

9. Explain the construction and working principle of permanent-split single value capacitor-type single phase induction motor. Mention its applications.

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(DEE 211) - Anucdeanucde.info/DEC11QPS/36-BTEE2.pdf · 2012-02-12 · (15 1 = 15) Answer ONE...

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Transcript of (DEE 211) - Anucdeanucde.info/DEC11QPS/36-BTEE2.pdf · 2012-02-12 · (15 1 = 15) Answer ONE...