ldsf ;lk; dfssdfsdf ldfljd kljkdfjsdfsdfsdf · 2011-06-11 · (b) Establish the relationship between charge and energy. (c) Draw the V-I characteristics of an ideal voltage source

(DEE 211)

B.Tech. DEGREE EXAMINATION, MAY 2011.

(Examination at the end of Second Year)

Electricals and Electronics

Paper I — MATHEMATICS — III

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

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

(4 ´ 15 = 60)

1. (a) Define odd and even function.

(b) Write the Fourier series for )(xf in the internal lcxc 2+<< .

(c) State the Fourier expansion of full wave rectifier.

(d) State the Eulers formula. Give the formulae to calculate its coefficients in the interval )2,( paa + .

(e) State the change of scale property of Fourier transformation.

(f) Find the Fourier sine transform of x1 .

(g) Write the inversion formula for the Fourier sine transform.

(h) State the geometrical significance of the regula-falsi (false position) method.

(i) Define d . Show that 2/1Ed=D .

(j) Prove that 11 --=Ñ E .

(k) State the Newtons forward difference interpolation formula.

(l) State the Sitrlings interpolation formula.

(m) State the Simpsons 31 rule of integration.

(n) State the Euler's method of finding an approximate solution of an initial value problem of first order.

(o) State the basic advantage of Rung-Kutta method over the Taylor series method.

(DEE 211) 2

UNIT I

2. (a) Obtain the Fourier series for xexf -=)( in the interval p20 << x .

(b) Let ppp

p

<<-=

<<=

xx

xxxf

2;

20;)(

. Expand )(xf as half range cosine series.

Or

(c) For a function defined by pp <<-= xxxf ,||)( obtain a Fourier series. Deduce that

...51

31

11

222 +++ = 8

2p .

(d) State and establish the Parseval's formula for the Fourier Series of )(xf converging uniformly in ),( ll- .

UNIT II

3. (a) Find the Fourier cosine transform of 211)(

xxf

+= . Hence derive the Fourier sine

transform of 21)(

xxx

+=f .

Or

(b) Explain the Gauss-Seidel iteration method of solving a system of linear equations. Compare the efficiency of this method with the Jacobi method. Solve the system of linear equations by Gauss-Seidel method. ,18203;17220 -=-+=-+ zyxzyx

252032 =+- zyx .

UNIT III

4. (a) Give the values of x and x10log :

x : 300 304 305 307 310

xxf 10log)( = : 2.4771 2.4829 2.4843 2.4871 2.4914

Find 310log10 using the Lagranges interpolation and Newtons divided difference interpolation formulae. Make a comment over the interpolate obtained.

Or

(DEE 211) 3

(b) Give the following values of x and y

x : 1.0 1.1 1.2 1.3 1.4 1.5 1.6

y : 7.789 8.403 8.781 9.129 9.451 9.750 10.031

Find dxdy and 2

2

dxyd at (i) x =1.1 (ii) x = 1.6.

UNIT IV

5. (a) Using the Runge-Kutta method of Fourth order, find an approximate value of y when 2.1=x in steps of 1.0 , given the initial value problem :

22 yxdxdy

+= and 5.1)1( =y

Or

(b) Solve the partial differential equation )10(10 222 ++-=Ñ yxu over the square with sides yxyx ==== 3,0 with 0=u on the boundary. Take the mesh length equal to 1.

—————————

(DEE 212)




Paper II — NETWORK ANALYSIS – I

Time : Three hours Maximum : 75 marks Answer question No. 1 compulsorily.

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

(4 × 15 = 60) 1. (a) Define a unit charge. (b) Establish the relationship between charge and energy. (c) Draw the V-I characteristics of an ideal voltage source. (d) Give the energy stored in an ideal Inductor. (e) Give the application of reciprocally theorem. (f) What is the limitation of superposition theorem? (g) What is the Rth of the following circuit?

(h) What is impedance expression for an RLC series circuit? (i) Define time constant of an RC circuit. (j) What is the Q-factor of an RL circuit? (k) What is the significance of bard width? (l) State the definition of current locus. (m) Define form factor. (n) Why power factor of a pure resistance is one?

UNIT I

2. (a) Identify the difference between active and passive elements. (b) Write the node equation for the circuit.

Or

(DEE 212) 2

3. (a) Explain star to delta transformation.

(b) Find the currents in the branches of the circuit.

UNIT II

4. (a) State and explain maximum power transfer theorem.

(b) Determine the r.m.s value of a single phase half wave rectified wave form.

Or

5. (a) Determine the average value of the following waveforms.

(b) Obtain the veins equivalent circuit for the following circuit.

UNIT III

6. (a) Explain the concept of resonance with respect to RLC parallel circuit.

(b) A 100V; 500 c/sec supply in connected atom the circuit given here, Draw the vector diagram for the arrangement.

Or

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

(b) A coil of inductance 9H ad resistance of 50 Ω in series with a capacitor is supplied at constant voltage from a variable frequency source. If the maxim current of 1A occur of 75+13, Find the frequency when the current is 0.5 A.

(DEE 212) 3

UNIT IV

8. (a) State and prove final value theorem. (b) Explain how the given RLC series circuit can be modelled using PSPICE.

Or

9. (a) Narrate the important features of PSPICE. (b) Determine the necessary values of V and i.

————————

(DEE 213)




Paper III — ELECTRONIC DEVICES

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

(15 × 1 = 15)

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

1. (a) Define electrostatic deflection.

(b) Define Magnetic deflection.

(c) Draw the Block diagram of CRO.

(d) What are the properties of semiconductor?

(e) What is Impurity?

(f) How will you get N-type material?

(g) Define diffusion capacitance.

(h) Define transition capacitance.

(DEE 213) 2

(i) Define S' and S".

(j) Write the relation between µ, gm.

(k) Write advantages of JFET over RJT.

(l) Justify FET is voltage controlled device.

(m) Draw the equivalent CKT of UJT.

(n) Differentiate between ϕ. TRIAC and DIAC.

(o) Define firing angle in SCR.

UNIT I

2. (a) Explain the magnetic deflection in CKT.

(b) Explain the motion of charged particles in magnetic field and mentioned their path.

Or

3. (a) Derive the expression for conductivity of a semiconductor and define law of Mass action.

(b) Explain the concepts of Intrinsic and Extrinsic semiconductors with reference to Atomic structures.

(DEE 213) 3

UNIT II

4. (a) Explain the V-I characteristics of a Diode and how there are effect with temperature.

(b) Explain the operation of Tunnel Diode.

Or

5. (a) Explain how zener diode act as voltage Regulator.

(b) Explain the operation of LCD.

UNIT III

6. (a) Describe the operation of CE configuration and analyse the current components in a transistor.

(b) What is Biasing and explain the stabilization?

Or

7. (a) What is compensation and explain different types of compensation techniques?

(b) Derive the relationship between α, β,γ .

(DEE 213) 4

UNIT IV

8. (a) Explain the principle operation of Enhancement MOSFET.

(b) Explain different Biasing methods in FET.

Or

9. (a) Define Intrinsic stand off Ratio of UJT, an UJT has RBB = 10 KΩ and RB2 = 3.5 kΩ find its Intrinsic stand off Ratio.

(b) Explain the operation SCR and draw its V-I characteristics.

–––––––––––

(DEE 214)




Paper IV — ELECTRICAL AND ELECTRONICS ENGINEERING MATERIALS



(4 × 15 = 60)

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

(b) Give few examples of insulators. (c) Mention few examples of extrinsic semi

conductors. (d) What is meaning of penetration depth? (e) Define ‘Ferrites’. (f) What is the meaning of Paramagnetism

define? (g) Give few examples of dielectric materials. (h) What are the characteristics of nanotubes?

(DEE 214) 2

(i) State Weidmann-Franz law.

(j) Define ‘Brillouin zones’.

(k) Define fermilevel in intrinsic and extrinsic semiconductors.

(l) Define super conductivity.

(m) Classify the magnetic materials.

(n) Define Polarizability.

(o) What are the applications of Piezoelectricity.

UNIT I

2. (a) Explain briefly the electrical characteristics of carbon nano tubes and also specify the applications of carbon nano tubes.

(b) Explain briefly the synthesis of nano wires.

Or

3. (a) Discuss the applications of nano structured materials.

(b) Explain the properties of carbon nano tubes.

(DEE 214) 3

UNIT II

4. (a) Explain the Band theory of solids.

(b) Explain in detail the fabrication of IC chip.

Or

5. What is Fermi level? Derive an expression for the fermi energy interms of the number of electrons per unit volume. Explain the Brillouin Zones.

UNIT III

6. (a) Explain in detail about type I and type II super conductors.

(b) What are the characteristics of ferites and mention its applications?

Or

7. (a) What is super conductivity? Explain Meissner effect.

(b) Briefly describe the weiss molecular theory of ferromagnetism and derive the curie-weisslaw.

(DEE 214) 4

UNIT IV

8. (a) Derive clasius-Mossotti relation and define polarization. Also classify the dielectrics.

(b) On what factors does the breakdown voltage of a dielectric material depend? What is the mechanism of thermal breakdown?

Or

9. (a) What are the different types of dielectric breakdown and explain?

(b) Explain different polarization mechanism in detail.

——————

(DEE 215)

B.Tech. DEGREE EXAMINATION, MAY 2011. (Examination at the end of Second Year)

Electricals And Electronics

Paper V — DIGITAL ELECTRONICS

Time : Three hours Maximum : 75 marks

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

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

1. (a) perform the subtraction using 2’s complement

(i) 1010100–101000 (ii) 11–1011 (b) What are PLD’s? (c) Convert the given gray code to binary

100100101111. (d) Realize three i/p NOR gate using zi/p NOR

gates. (e) Draw the circuit of CMOS NAND gate. (f) Realize full adder using half adders.

(DEE 215) 2

(g) Draw the characteristic table of T flipflop. (h) Enumerate the difference between

synchronous and asynchronous sequential circuits.

(i) Draw the internal diagram of a 4 × 1 multiplexer using NAND gates.

(j) What are MINTERMS and MAXTERMS? (k) What is the difference between canonical and

standard SOP? (l) Convert ( ) ( )6,5,3,1,, Σ=CBAF to canonical

POS. (m) State DeMorgan;s Laws. (n) What are the advantages of TTL family? (o) What is a slip flop?

UNIT I

2. (a) Implement using only NAND gates

( ) ( )12,9,8,4,3,2,1,0,,, Σ=DCBAF

(b) Simplify

(i) ( ) CBAACAB ′+′+

(ii) ( )( )DCDCBAAB ′+′′′+

Or

(DEE 215) 3

3. (a) Reduce the Boolean expressions

(i) ( ) ( )CBBCBAAB ++++

(ii) ( ) ( )CABCBAACAB ++′+′+

(iii) ( )( )′+′+ ABAAB

(b) Minimize using K-maps.

( )31,30,28,24,22,15,14,13,6,5,4,1,0Σ=F

UNIT II

4. (a) Explain carry look ahead adder.

(b) Design a Excess-3 code adder using 4 bit parallel adder and logic gates.

Or

5. (a) Implement the following functions using 4 × 16 decoder

( )15,14,13,12,11,8,7,4,2,11 Σ=f

( )15,9,8,5,3,1,02 Σ=f

( )7,4,3,23 Σ=f

( )9,7,4,3,14 Σ=f

(b) What is decoder and encoder?

(DEE 215) 4

UNIT III

6. (a) Design a MOD 13 counter using JK flip flop. (b) Convert a given JK flipflop to RS flipflop.

Or

7. (a) Explain 4 bit shift register. (b) Explain 4 bit BCP ripple counter.

UNIT IV

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

(b) Implement a PLA structure for a full adder. Or

9. (a) Draw the circuit of a 3i/p TTL totempole NAND gate and explain its operation.

(b) Write short notes on PLDs.

——————

(DEE 216)



Paper VI — ELECTRO MECHANICS — I


(15) Answer ONE question from each Unit.

(4 × 15 = 60) 1. (a) Define field energy. (b) What is electric field energy? (c) What is torque in a magnetic field system? (d) What is the rotating part in a DC generator? (e) What is wave winding? (f) What is the function of field system? (g) For 6 pole D.C generator. What is the

number of interpoles? (h) Give applications of DC series generator. (i) What is the useful feature of back emf? (j) Give applications of D.C shunt motor. (k) Draw the configuration of long shunt

compound motor.

(DEE 216) 2

(l) What is the function of overload relay in a 3-point starter?

(m) What is the limitations of Swinburne’s test? (n) What is the advantage of Hopkinson’s test? (o) Define efficiency of D.C. generator.

UNIT I 2. (a) Explain energy balance. (b) Two compiled coils have inductance value as,

( )xL 1111 += ; ( )xL 15.022 += ; ( )xLL 12112 == . These expression are valid over a certain range of linear displacement x , in curve. The first coil is excited by a constant current of 20 A and the second by 10A, find mechanical work done if ‘x’ changes from 0.5 to 1.0 cm.

Or (c) Explain dynamically induced emf. (d) Explain the role of air gap in electro

mechanical energy.

UNIT II 3. (a) Explain commutation in a D.C. generator. (b) A fan pole generator having wave would

armature winding has 51 slots, each containing 20 conductors, speed of the generator is 1500 rpm and flug per pole in 7.0 mb. Calculate the generated voltage.

Or

(DEE 216) 3

(c) Explain load characteristics of a D.C. shunt generator.

(d) An 8 pole generator has an output of 200 A at 500 V, the lap connected armature has 1280 conducts, 160 commutative segments. If the brushes are advanced 4-segments from the no-load neutral axis, estimate the armature de-magnetising and cross-magnetising ampere-turns per pole.

UNIT III

4. (a) What are the conditions to be satisfied for the parallel operation of two D.C. series generators?

(b) A 4 pole DC motor taken an armature current of 150 A at 440V. If armature resistance is 0.15 Ω ; Calculate the value of back e.m.f. at this load.

Or

(c) Explain the load characteristics of a DC compound motor.

(d) A 4 pole, lap connected dc motor has 576 conductors and draws an armature current of 10 A. If the flug per pole is 0.02 wb. Calculate the armature torque developed.

(DEE 216) 4

UNIT IV

5. (a) Explain Swinburne’s test in detail.

Or (b) Write a short notes on principle and working

of amplidyne.

——————

(DEE 217)



Paper VII — ENVIRONMENTAL STUDIES


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


1. Explain the following in 1 or 2 sentences :

(a) Define the term ‘‘Ecosystem’’.

(b) What are Herbivores?

(c) What is a food chain? Illustrate.

(d) Distinguish between renewable and non-renewable sources of energy.

(e) Mention two values of biodiversity.

(f) What is vermicomposting?

(g) What are the sources of water pollution?

(DEE 217) 2

(h) Define ‘‘sustainable development’’.

(i) What is meant by ‘‘Rain water harvesting’’?

(j) What is the significance of Ralegaon Siddhi?

(k) What are the effects of noise pollution?

(l) What is Eutrophication?

(m) What are Acid Rains?

(n) What are the pollutant responsible for ozone depletion?

(o) Why are forests regarded as ‘Lungs of the Earth’?

UNIT I

2. Explain the importance of forests. Or

3. What is a ‘Resource’? Give the classification of natural resources.

UNIT II

4. What are the threats to Biodiversity? Explain. Or

5. Define air pollution. What are the various indoor air pollutants and what are their effects on human health?

(DEE 217) 3

UNIT III

6. What are the effects of urbanisation and industrialisation on environment?

Or

7. What is sustainable development? What are the strategies for sustainable development?

UNIT IV

8. Explain the salient features of Environmental Protection Act.

Or

9. Write short notes on :

(a) Aquatic ecosystems.

(b) Coastal zone regulations.

——————

(DEE 221)




Paper I — MATHEMATICS — IV

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


(4 × 15 = 60)

1. (a) Define an analytic function )(zf .

(b) What is the necessary condition for the existence of the derivative of the complex function )(zf ?

(c) What are the real and imaginary parts of zzf cosh)( = .

(d) Show that the function 23 3xyxu −= is a harmonic function.

(e) State Cauchy-Integral formula.

(f) State the Laurent Theorem for the complex function )(zf .

(g) Define the removable singularity of the analytic function )(zf with example.

(h) State Cauchy-Residue theorem.

(i) Determine poles of .)(

cot)( 2azzzf

−=

π

(j) Calculate the residue of 1

)( 2

3

−=

zzzf at ∞=z .

(k) Evaluate ∫ +C zdz ,

2 where C is 1|| =z .

(l) Write the generating function of Bessel equation.

(m) Write the orthogonal property of Legendre polynomial.

(n) Write the value of )(2 xP of Legendre polynomial.

(o) Define regular singular point of a differential equation.

(DEE 221) 2

WS18

UNIT I

2. (a) Determine the analytic function ivuzf +=)( if ,vu − ]sin[cos yyex − .

(b) Show that a harmonic function satisfies the formal differential equation 02

=∂∂

∂zz

u .

Or

3. (a) Prove that the function )(zf defined by 0)0(),0()1()1()( 22

33=≠

+−−+

= fzyx

iyixzf is

continuous and the Cauchy-Reimann equations are satisfied at the origin, yet )0('f does not exist .

(b) Show that the function ||)( xyzf = is not an analytic function at the origin even though C.R. equations are satisfied there at the origin.

UNIT II

4. (a) Using Cauchy integral formula evaluate ∫ −−C

z

zze

)2()1(

2 dz where C is the circle

3|| =z .

(b) Obtain the Taylor and Laurent series which represent the function )3()2(

1)(2

++−

=zz

zzf

in the regions (i) 2|| <z (ii) 3||2 << z (iii) 3|| >z .

Or 5. (a) State and prove Taylor's Theorem for the analytic function )(zf .

(b) Find the Taylor expansion of 2)1(1)(+

=z

zf about the points iz −= .

UNIT III

6. (a) Evaluate ∫

−C z

z2

2

6

sinπ

dz where C is the circle .2|| =z

(b) Using Cauchy Residue theorem prove that

∫ −

π

θθ

0 cos817d =

15π .

Or

7. (a) Solve in series the differential equation 023 2

2=++ y

dxdy

dxydx .

(b) By using Cauchy Residue theorem show that ∫ −=+

α π

022 2

sin aeaxxx .

UNIT IV

(DEE 221) 3

WS18

8. (a) Show that )()()12()()1( 11 xnPnxPnxPn nnn −+ =+=+ .

(b) Derive the Rodrigue's formula of the Legendre polynomial.

Or

9. (a) Prove that ∫ =1

0

0)()( xBJxxJ nn α for βα ≠ and 21 )]([

21 α+nJ for βα = . Here α and

β are the roots of the Bessel equation 0)( =xJn

(b) Prove that

(i) )]()(2)([41)(" 22 xjxJxJxJ nnnn +− +==

(ii) [ ] )]()([)()( 21

21 xJxJxxJxxJ

dxd

nnnn ++ −=

—————————

(DEE 222)




Paper II — ELECTRONIC CIRCUITS – I


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

Answer ONE question from each Unit. (4 × 15 = 60) 1. (a) What is a valve? (b) What is the advantage of bridge rectifier over

full wave rectifier? (c) What is the purpose of a filter? (d) What do you mean by ramp input? (e) What is the difference between clipping and

clapping? (f) What do you mean by low frequency model

of transistor? (g) Define output impedance of FET.

(DEE 222) 2

(h) What is transconductance of FET? (i) Define cut-off frequency. (j) What is leakage current in BJT? (k) What is operating point of transistor? (l) What is high frequency response of BJT? (m) What is drift current? (n) What is the effect of coupling capacitor in

amplifiers? (o) What is the purpose of multistage

amplifiers?

2. (a) Explain the different methods of full wave rectifications of 1 φ alternatry source using diode, illustratory their merits and demerits. (8)

(b)

Fig.1.

–

(DEE 222) 3

Determine the output waveform for the network shown in fig(1) and compute output DC level and required PIV of each diode. (7)

Or 3. (a) Obtain the RC high pass filter response for

pulse input. (7) (b) Explain the types and applications of clipper

circuits. What is the procedure of analysing the clipper circuits. (8)

4. (a) Explain the small signed low frequency model of transistor with its modes of operation. (8)

(b) Describe various operating points within the limits of operation of a transistor. (7)

Or 5. For the Fig(2), determine IB, IC, VCE, VC, VE, VB,

VBC. (15)

Fig(2)

(DEE 222) 4

6. (a) Obtain the hybride PI model of BJT in CE configuration and derive the expressions for current gains and voltage gains. (8)

(b) A BJT has IE = 2.5 MA, hfe = 140, hoe = 20 sµ ( )mhoµ and shob µ5.0= determine the

(i) CE hybride equivalent circuit. (ii) C – B re model. (7)

Or

7. (a) What is a Cascade system? Explain its advantages and applications. (7)

(b) Obtain the two stage transistor amplifier circuit model at low frequencies. (8)

8. (a) Obtain the small signal model of FET and analyse the transfer characteristics. (8)

(b) Determine the high frequency response of CE-CE cascaded amplifier. (7)

Or

9. (a) Explain the CS/CD amplifier operation of high frequencies. (8)

(b) For a CE amplifier if R2 = RS = 1000 and hie =100, hre = 2.5 × 10-4, hfe = 50, hoe = 25 µ a/v. Find Ai, Ri, Av, Avs, Ais. (7)

–––––––––––

(DEE 223)




Paper III — ELECTROMAGNETIC FIELD THEORY




1. (a) What is a Point Charge? (b) Define electric field intensity. (c) What is electric dipole? (d) State Gauss’s law. (e) State Ohm’s law in Point form. (f) Write the Poisson’s equation. (g) State any two methods of producing

magnetic field. (h) State Ampere’s current law.

(DEE 223) 2

(i) A circular wire of radius ‘R’ is carrying a current of ‘I’ A. What is the value of ‘H’ at the centre of the wire?

(j) State Lenz’s law. (k) For stationary current fields, what is the

value of J.∇ ? (l) What is Mutual inductance? (m) What is skin effect? (n) State poynting theorem. (o) What is a perfect dielectric?

UNIT I

2. (a) What are the applications of Gauss’s law? Derive the boundary conditions at a conductor dielectric interface by applying Gauss’ law. (8)

(b) A uniform sheet of charge with 2/

31 mncs π

ρ −= is located at z = 5 m and

uniform line charge with mnc /925−

=λ at

.3,3 mymz =−= Find E at (x, -1, 0) m. (7)

Or

(DEE 223) 3

3. (a) What is the general procedure of solving laplace and poisson’s equations? Obtain the capacitance of parallel plate capacitor using Laplace equation. (8)

(b) Derive the expression for electric field intensity due to a point charge at rest. (7)

UNIT II 4. (a) State and explain Biot – Savart’s law

relating to the magnetic field produced at a point due to the current in a small electric wire. (8)

(b) Define Scalar magnetic potential and show that ,mVH ∇−=

rWhere mV is scalar

magnetic potential. (7) Or

5. (a) Derive Maxwell’s curl equation for steady magnetic fields. (8)

(b) Find H at (0, 0, 4) and (0, 0, –4) for a circular loop located on 0,922 ==+ zyx carries a direct current of 8A along a φ . (7)

UNIT III 6. (a) What is Maxwell’s first curl equation the

electromagnetic fields. Explain Faraday’s law in differential term. (8)

(b) Derive expression for energy stored in negative field in terms of vector potential. (7)

Or

(DEE 223) 4

7. (a) State and explain the modified Ampere’s Circuital law in integral form and in differential form. (8)

(b) What are magnetic boundary Conditions? Explain? (7)

UNIT IV

8. (a) Derive an expression for wave equation in free space. (10)

(b) A magnetic field intensity of a uniform plane wave in air is 10 A/m is ay direction. The wave is propagating in a 2 direction at a frequency of rad/sec.104 9× Find the wave length and amplitude of E. (5)

Or

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

(b) What is poynting vector? State and prove poynting theorem.

———————

(DEE 224)




Paper IV — NETWORK ANALYSIS — II


1. (a) What is a planar circuit? (15 × 1 = 15)

(b) Define a oriented graph.

(c) What is the difference between branch and path?

(d) What is a port?

(e) What are admittance parameters?

(f) What is the laplace transform of a impulse signal?

(g) Define operational impedance.

(h) What is coefficient of coupling?

(i) What is a double tuned filter?

(j) What is band stop filter?

(k) What is the power factor of φ 3 system, if one of the wattmeter shows ‘0’ (zero) reading in two wattmeter method?

(l) What is the phase difference between line and phase voltages in a φ3 balanced systems?

(m) State Millman’s theorem.

(n) What is the importance of dot convention?

(o) What is meant by dual of network?

UNIT I

2. (a) Explain the basic terminology used in network graph theory (at least 7 terms). (7) (b) For the network shown in figure (1), develop the graph and obtain the tie-set matrix

selecting a tree. Obtain the dual of the network. (8)

Fig. 1

Or

(DEE 224) 2

3. (a) Explain the classification of networks. (5) (b) Obtain the interrelation between transmission and hybrid parameters. (5) (c) Find Z-parameter model of the circuit shown in figure 2. (5)

Fig. 2

4. (a) Obtain the impulse response of R-L-C circuit. (7) (b) Assume no initial charge on either of the capacitors in Fig. 3. The switch is closed at

0=t . Find ‘i’ at += 0t . Apply initial and final value theorem. (8)

Fig. 3

Or

5. (a) Obtain the network function for the network shown in fig. 4. (8)

Fig. 4 (b) What should be the value of ‘L’ such that ( ) 1=sZ in the network shown in fig. 5. (7)

Fig. 5

(DEE 224) 3

6. (a) What is coupled circuit? Find the drop across ‘ LR ’ in the circuit shown in Fig. 6. (8)

Fig. 6 (b) Explain the (i) properties, (i) use (iii) classification of filters. (7)

Or

7. (a) Obtain the frequency response characteristics of band pass filter. (7) (b) What is a tuned coupled circuit? Analyse the characteristics of single tuned coupled

coils. (8)

8. (a) What is a φ−3 system? Explain the advantages of three-phase system. (5)

(b) Obtain the relationship between phase and line voltages in a star connected systems. (5) (c) Show that apparent power in star connected system and delta connected system are

same. (5)

Or

9. (a) Explain, how the two-wattmeter method can be applied to measure the reactive power in φ3 system. Explain the variation in wattmeter reading with loads of different power factors. (7)

(b) Three impedances, Ω= o050AZ , Ω= 10jZB and Ω−= 10jZC are connected in star across a 100 V, 50 Hz balanced φ3 delta connected power supply. Find the drop across each impedance and the potential of the neutral. (8)

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(DEE 225)

B.Tech. DEGREE EXAMINATION, MAY 2011


Electricals and Electronics Engineering

Paper V — PRIME MOVERS AND PUMPS



Answer ONE question from each Unit. (4 × 15 = 60) 1. (a) Define Specific gravity. (b) What is meant by priming? (c) Define specific speed of a Turbine. (d) Define Degree of Reaction. (e) List out the limitations of 1st law of

thermodynamics. (f) Define Enthalpy and what are its units? (g) What is the function of flywheel in

IC Engine? (h) List out different methods of finding friction

power in IC engines. (i) List out important components of a Rankine

cycle.

(DEE 225) 2

(j) List out various methods of improving thermal efficiency of gas turbine plant.

(k) What are the limitations of gas turbine power plant?

(l) Define compounding of steam turbine. (m) Draw the P-V diagram of Otto cycle. (n) Define Clausious statement. (o) What is Quasi-Static process?

UNIT I 2. (a) Derive the equation for finding maximum

efficiency for force exerted by a jet of water on series of vanes.

(b) A jet of water having a velocity of 15m/sec, strikes a curved vane which is moving with a velocity of 5m/sec in the same direction as that of the jet at inlet. The vane is so shaped that the jet is deflected through °135 . The diameter of jet is 10 cm. Assuming the vane to be smooth, find

(i) Power exered on the vane (ii) Efficiency of the vane.

Or 3. (a) Define Specific speed of a Centrifugal Pump

and derive its equation. (b) Define cavitation in pumps. How to avoid

cavitation. What are its effects?

(DEE 225) 3

UNIT II 4. (a) Derive the equation for finding maximum

efficiency of a Pelton Turbine. (b) A pelton wheel is to be designed for a head of

60m when running at 200 rpm. The pelton wheel develops 130 shaft horse power. The velocity of the bucket is 0.45 times the velocity of the jet, overall efficiency is 0.85 and co-efficient of velocity is equal to 0.98.

Or 5. (a) Define Draft tube. What are various types of

Draft Tubes? Why Draft Tubes are necessary for Reaction Turbines and where it is connected?

(b) Explain in detail constant speed and constant head characteristic curves of hydraulic turbines.

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 =3.1PV constant, until the volume is 0.8 m3. Calculate the work done in each process.

Or 7. (a) Derive steady flow energy equation. (b) Derive the equation for finding efficiency of

Carnot Cycle.

(DEE 225) 4

UNIT IV

8. (a) Explain with neat sketch working of 2-stroke petrol engine.

(b) The output of a single cylinder four stroke IC engine measured by a rope brake dynometer. The diameter of the brake pulley is 750 mm and rope diameter 50m. The dead load on the tight side of the rope is 400 N and the spring balance reading is 50 N. The bore is 150 mm stroke is 190 mm. The engine consumes 4 Kg/Hr of fuel at rated speed of 1000 rpm. The mechanical efficiency of the engine is 89%. The calorific value of the fuel is 44 MJ/Kg. Calculate the brake specific fuel consumption, bmep and brake thermal efficiency.

Or

9. (a) Explain with a neat sketch pressure and velocity compounding of steam turbines.

(b) Draw the combined velocity triangles of an Impulse Steam Turbine and derive its equation for finding maximum efficiency.

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(DEE 226)



Electricals and Electronics Engineering

Paper VI — ELECTRO MECHANICS – II

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


(4 × 15 = 60) 1. Write briefly on the following : (a) What is the function of a transformer? (b) How the windings are classified? (c) Define voltage regulation of a transformer. (d) On which side of the transformer, the S-C

test is conducted? why? (e) Why transformer is rated is KVA? (f) Why tap changing are provided in

transformer? (g) What is an Auto Transformer? (h) Write any two types of cooling systems

provided in a transformer. (i) What are types of squirrel case Induction

motors?

(DEE 226) 2

(j) What is stalling torque? (k) On what factors Eddy current losses of an

Induction motor depend? (l) What is the function of a star – Delta

starter? (m) Give the applications of shaded pole motor. (n) What are the limitations of capacitor start

motor? (o) Explain the advantages of ‘sumpner’s Test’?

UNIT I 2. (a) Derive the equation to determine the emf

induced in a transformer. (b) Calculate the regulation of a transformer in

which ohimc losses are 1 % of the output and the reactance drop in 5 % of the voltage, when the p.f. in 0.8 lag and 0.8 lead.

Or 3. (a) Develop the equivalent circuit of a single

phase transformer. (b) A transformer of rating 20 KVA, 2000/ 200 V

has the following parameter: Rep (on HV side) = 2.56 Ω ; Zep( on HV side) = 4.23 Ω ; core loses and 95

w at rated voltage. Calculate the transformer efficiency when delivering 20 KVA at 200 V at 0.8 pt lagging.

(DEE 226) 3

UNIT II 4. (a) Explain the parallel operation and loading

sharing in transformers. (b) An 11500/2300 V transformer is rated at

100 KVA as a two winding transformer. If the two windings are converted in series to form an auto – transformer, what will be the possible voltage ratios?

Or 5. (a) Explain the scott connection of transformer. (b) Two single phase transformer A and B are

rated at 250 KVA. each are operated in parallel on both sides. percentage impedances are )61( j+ and )8.42.1( j+ fw A and B resp. Compute the load shared by each when the total load is 500 KVA at 0.8 pt lagging.

UNIT III 6. (a) Explain how torque is produced in an

Induction motor. (b) An 18.65 kW, 6 pole, 50 Hz, φ−3 ship ring

induction motor runs at 960 rpm on full load with a rotor current per phase of 35 A. Allow 1 Kw for mechanical losses. Find the resistance per phase of 3 – phase rotor winding.

Or

(DEE 226) 4

7. (a) Explain No-load and blocked rotor test on 3 phase Induction motor.

(b) A 3 phase induction motor is driving full load torque which is independent of speed. If the line voltage drops to 90 % of rated value. find the increase in motor copper losses.

UNIT IV

8. (a) Explain direct on line starter. (b) Explain why single phase Induction motor is

not self starting.

Or

9. (a) Explain the operation of shaded pole type motor.

(b) What are Induction generators and give their application?

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Documents

ldsf ;lk; dfssdfsdf ldfljd kljkdfjsdfsdfsdf · 2011-06-11 · (b) Establish the relationship between charge and energy. (c) Draw the V-I characteristics of an ideal voltage source