VARDHAMAN COLLEGE OF ENGINEERING...A square prism of side of base 55 mm and axis height 90 mm is...

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VARDHAMAN COLLEGE OF ENGINEERING (AUTONOMOUS)

B. Tech II Semester Regular Examinations, June - 2015 (Regulations: VCE-R14)

ENGINEERING DRAWING - II (Common to Mechanical Engineering & Civil Engineering)

Date: 15 June, 2015 FN Time: 3 hours Max Marks: 75

Answer ONE question from each Unit All Questions Carry Equal Marks

UNIT-I

1. A square prism of side of base 55 mm and axis height 90 mm is resting on H.P. on its base such that all the edges of the base are equally inclined with the V.P. One triangular hole of side of base 30 mm is cut through the square prism such that the axis of the square prism and the triangular hole are the same and one of the sides of the triangular hole is parallel with the one of the sides of the square prism. One cutting plane which is perpendicular to V.P. and inclined at an angle 60° with H.P. and bisecting the axis of the prism is cutting the object. Draw front view, sectional top view and true shape of the prism.

15M

2. The cylinder of diameter of base 50 mm and axis height 60 mm is resting on its base on H.P. as shown in Fig.1 below. Develop the surface of the cylinder.

Fig.1

15M

UNIT-II

3. A cone with a base diameter of 64 mm and an axis length of 70 mm is kept on its base on the HP. A cylinder of diameter 30 mm and length 90 mm penetrates the cone horizontally. The axis of the cylinder is 20 mm above the base of the cone and 5 mm away from the axis of the latter. Draw the three views of the solids showing curve of intersection.

15M

4. A vertical cylinder of 80 mm diameter is completely penetrated by another cylinder of 60 mm diameter, their axes bisecting each other at right angles. Draw their projections showing curves of penetration, assuming the axis of the penetrating cylinder to be parallel to the VP.

15M

UNIT-III

5. A compound solid consists of a frustum of a cone and a hexagonal prism. The frustum of the cone is resting on the top of the prism. The frustum of the cone has the bottom base of diameter 50mm, top face diameter 30mm and length of the axis is 80mm. The sides of the hexagonal prism are 35mm and the axis is 20mm long. Draw the isometric projection of the compound solid.

15M

:: 2 ::

6. A cylinder of height 65 mm and diameter 40 mm is resting on its base on the HP. It is cut by

a plane perpendicular to VP and inclined at 30º to the HP. The plane passes through a point on the axis located at 25 mm from the top. Draw the isometric projection of the cut cylinder.

15M

UNIT-IV

7 Three views of a machine part are shown in Fig.2 given below. Draw the isometric view of the part (All dimensions are in mm).

Fig.2

15M

8. Draw the elevation, plan and right side view of the part shown in Fig.3 below. (All dimensions are in mm).

Fig.3

15M

UNIT-V

9. A rectangular pyramid, base 30 mm x 20 mm and axis 35 mm long, is placed on the ground plane on its base, with the longer edge of the base parallel to and 30 mm behind the picture plane. The central plane is 30 mm to the left of the apex and station point is 50 mm in front of the picture plane and 25 mm above the ground plane. Draw the perspective view of the pyramid.

15M

10 A cylinder 30mm diameter and 40mm long is lying on the ground with its axis perpendicular to the picture plane. The nearest point of contact with the ground is 60mm on the left of the station point and 10mm from the PP. The station is 40mm above the ground and 60mm in front of the PP. draw the perspective view of the cylinder.

15M



B. Tech II Semester Regular Examinations, June - 2015 (Regulations: VCE-R14) MATHEMATICS - II

(Common for All Branches) Date: 17 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) Define rank of a matrix. Also find the rank of the matrix A by reducing to echelon form

where

0 1 3 11 0 1 13 1 0 21 1 2 0

A

7M

b) State and verify Cayley‐Hamilton theorem for the matrix

1 42 3

A

and find its inverse.

Also express 5 4 3 24 7 11 10A A A A A I as a linear polynomial in A

8M

2. a) Solve the following system of equations by Gauss elimination. 2 6 11 0,6 20 6 3 0, 6 – 19 1 0x y x y z y z

7M

b) Using Cayley-Hamilton theorem find 4A from

342234423

A

8M

Unit – II

3.

a) Find the eigen values and eigen vectors of

1 0 11 2 12 2 3

A

and also write the

algebraic multiplicity and geometric multiplicity of each eigen value.

8M

b) Reduce the quadratic form 2 2 21 2 3 2 3 1 22 2x x x x x x x to canonical form. 7M

4.

a) Are the vectors (3,2,7), (2,4,1) and (1,-2,6) linearly dependent? If so find the relation between them.

7M

b) Compute the modal matrix for the quadratic form 2 2 21 2 3 2 33 3 2x x x x x

8M

Cont…2

::2::

Unit - III

5. a) Find the PDE of all spheres of fixed radius having the centers in xy-plane.

7M

b) Solve 022

2

yz

xz

xz

by the method of separation of variables.

8M

6. a) Form a partial differential equation by eliminating the arbitrary function from

)()( 22 yxfyxz

8M

b) Solve 2 2 2 2p q x y 7M

Unit – IV

7.

a) Obtain the Fourier series for the function

30210321

)(xinxxinx

xf

8M

b) Express 22 xx in ,0 as the half-range sine series.

7M

8. a) Obtain the Fourier series expansion of xxf cos1 in 0 2x

8M b) Compute the half-range Fourier cosine series representation for:

xinxk

xinkxxf

2

20

7M

Unit – V

9.

a) Find the Fourier transform of

21 1( ) ,

0 1

x if xf x

if x

hence evaluate

dxxx

xxx

2cos

sincos3

0

8M

b) Find the Fourier sine transform of xe . Hence show that

21

sin2

0

medx

x

mxx

, 0 m

7M

10.

a) State convolution theorem and hence find

23

21

zzzZ

7M

b) Using the z-transforms, solve 2 12 3 5n n nu u u n with 0 1 0u u 8M




ENGINEERING PHYSICS (Common to Computer Science and Engineering, Information Technology & Electrical and

Electronics Engineering) Date: 19 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) What are Miller indices? Find the expression for interplanar spacing in terms of Miller Indices.

7M

b) Derive Bragg’s law. X-ray analysis of a crystal is made with X-rays of wavelength 0.58Ao, Bragg’s reflections are obtained at angles 6.45o and 13o. Calculate the interplanar spacing.

8M

2. a) Describe Debye-Scherer powder method to determine the interplanar spacing of the crystal by X-ray diffraction.

7M

b) Compare the properties of sc, bcc and fcc based on number of atoms, atomic radius, co-ordination number and packing fraction. Sketch the following in the unit cell

1 2 3 , 1 10 and 1 01 , 1 0 0

8M

Unit – II

3. a) What is de Broglie’s hypothesis in relation to matter waves? If is the frequency and λ the wavelength of matter waves associated with a freely moving particle then show that λ2 = constant.

6M

b) What are matter waves? A particle of mass 0.5MeV/c2 has kinetic energy 100eV. Find the de-Broglie wavelength. Here c is velocity of light.

9M

4. a) Explain the working of a semiconductor laser? 8M b) Draw a curve representing the variation of the conductivity of an extrinsic semiconductor

as a function of temperature and explain the behavior. 7M

Unit – III

5. a) What is internal (local) field? Derive an expression for internal field in case of 1-d array of atoms in dielectric solid.

9M

b) Explain the synthesis of nano materials by sole-gel method. Mention the advantages.

6M

6. a) Explain ferro-electricity and peizo-electricity and mention their applications. 9M b) How top-down approach differs from bottom-up approach. Give examples. 6M

Unit – IV

7. a) Distinguish between dia-, para- and ferro-magnetic materials based on their susceptibilities.

7M

b) Explain Weiss theory of ferro-magnetism.

Cont…2

8M

::2::

8. a) Explain what is Meissner’s effect? Why is it necessary to have a weak magnetic field to

observe this effect? 7M

b) Draw diagrams representing the behavior of magnetization M as a function of the applied magnetic field for type I and II superconductors.

8M

Unit – V

9. a) Explain the mechanisms by which radiation interacts with matter. What are Einstein’s coefficients?

7M

b) Using a suitable energy level diagram explain the working of a He-Ne laser. For semiconductor laser the band gap is 0.80eV, what is the wavelength of light emitted from it?

8M

10. a) i. Classify optical fibers according to the refractive index profiles ii. What are the extrinsic causes for attenuation of signals in optical fiber

9M

b) Explain numerical aperture. Find the attenuation in an optical fiber of length 500m, when light signal of power 100mW emerges out of the fiber with power of 90mW.

6M



B. Tech II Semester Regular Examinations, June - 2015 (Regulations: VCE-R14) TECHNICAL ENGLISH

(Common to Electronics and Communication Engineering, Mechanical Engineering & Civil Engineering)



Unit – I

1. a) In ‘Heaven’s gate’, how has the author given a description of Ladakh from four Quarters? Write briefly.

10M

b) Do as directed. i. Write the antonym for the word : efficient ii. Write the synonym for the word : compassion iii. Choose the appropriate article : My teacher advised me to read _____ Bible iv. Choose the appropriate word : I buy _____ in the shop. (stationery, stationary) v. Correct the error : Neither Raju nor John are present today

5M

2. a) Mother Teresa is an embodiment of all finer and nobler values of life. Justify the statement.

10M

b) Do as directed: i. Write the antonym for the word : genuine ii. Write the synonym for the word : enhance iii. Use the following homonyms in your own words: difference, deference iv. Choose the appropriate preposition: _____ (Beside, Besides) being a good teacher,

he is also a good speaker v. Correct the error : Latha is a tallest girl in our class

5M

Unit – II

3. a) Justify the statement that Miss Krishna as a connoisseur. 10M b) Do as directed:

i. Write the antonym for the word : discipline ii. Write the synonym for the word : obstacles iii. Fill in the blank with appropriate article : Mr Sharma is ____ university professor iv. Correct the error : This book gives all informations v. Use this idiom in your own sentence : Cock and bull stories

5M

4. a) Describe the important contributions and achievements of Sam Pitroda to the field of telecommunication.

10M

b) Do as directed: i. Write the antonym for the word : fortunate ii. Write one word substitute : A person who doesn’t believe in God iii. Write the synonym for the word : industrious iv. Use the following phrasal verb in your own sentence : bring out v. Correct the error : Kashmir is more lovelier than any other

place in India

5M

Cont…2

:: 2 ::

Unit – III

5. a) Trace how Satyajit Ray has analyzed film making in Indian Film Industry in general, Bengali Film Industry in particular in his essay’, “The Odds Against Us”.

10M

b) Do as directed: i. Write the meaning of the word : affinity ii. Use suitable adverb in the sentence : Let us do yoga________ iii. Write one word substitute : Naturally existing in a place iv. Use this idiom in your sentence : to swoop down v. Correct the sentence : Count the number of participation

5M

6. a) Briefly mention the salient features of Martin Luther King’s speech, ‘I have a Dream’. 10M b) Do as directed:

i. Write the antonym of the word : despair ii. Write the synonym of the word : fatal iii. Write one word substitute : When a person is kept somewhere and is

not allowed to leave iv. Use this idiom in your sentence : to leave one battered v. Correct the sentence : A dog always goes besides its owner

5M

Unit – IV

7. a) i. Provide a short note on the account of damage caused by floods and tsunami to Cuddalore in 2004.

ii. Write a job application letter for a post of software engineer in any company of your choice.

10M

b) Do as directed: i. Write the antonym for the word : Achieve ii. Write the synonym for the word : Fertile Convert the following sentences into passive voice: i. Raghu ate six idils at dinner ii. Beautiful giraffes roam savannah iii. Mom read the novel in one day

5M

8. a) You are ManikTiwari of Gangaram Book Bureau, Bengaluru. You sell books on Engineering subjects. Write a letter to: The Sales Manager, Mcgraa Hills Publications, Safdar Jung Road, New Delhi-110001. i. Enquire about the possibility of being their distributor ii. Request for their Catalogue

8M

b) Draft an application for the position of Professor of Computer Science. Address your application to the Principal, NIT, Warangal.

7M

Unit – V

9. i. What are the major sources of tension today, according to Obama? ii. Imagine you are a reporter for The Daily Times newspaper. Write a report regarding the

recent train accident that took place in your city.

15M

10. Rotary club, Hyderabad has invited you to speak on the ‘Importance of English in the present context of globalization’. The participants are drawn from different colleges. Draft a speech.

15M




ENGINEERING CHEMISTRY (Common to Computer Science and Engineering, Information Technology & Electrical and

Electronics Engineering) Date: 22 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) Differentiate between primary and secondary cells. Describe with a neat diagram the construction and working of Lead-acid cell.

8M

b) What are concentration cells? Give an example. Derive an expression for the emf of concentration cell. Two electrodes are immersed in a solution of Zn ions of 0.1M and 0.02M concentration. Give the cell representation, reactions and calculate the emf of the cell at 298K.

7M

2. a) What is cathode protection? Explain the sacrificial anode method of prevention of corrosion.

6M

b) Define specific, equivalent and molar conductance. A conductance cell has two parallel plates of 1.25cm2 area placed at 10.50cm apart, when filled with a solution of an electrolyte the resistance was found to be 2.0 x 103 ohms. Calculate the cell constant and specific conductance of the solution.

9M

Unit – II

3. a) With a neat diagram explain the desalination of sea water by electrodialysis process. 7M b) Differentiate between temporary and permanent hardness of water.

A sample of water drawn by a jute mill near Hyderabad had the following analytical data: Mg(HCO3)2=16.8mg/L; MgSO4=24.0mg/L; CaCl2=8.2mg/L. Calculate the temporary, permanent and total hardness of the sample water. Given weights of Ca=40, Mg=24, Cl=35.5, C=12, S=32, O=16 and H=1.

8M

4. a) Describe ion-exchange process of treating water. Mention the advantages of this method.

8M

b) Give an account of: i. Colloidal conditioning ii. Phosphate conditioning iii. Calgon conditioning

7M

Unit – III

5. a) Differentiate between thermoplastic and thermosetting plastics with examples. 5M b) Give the preparation, properties and applications of poly vinyl chloride and Teflon.

10M

6. a) Discuss the merits and demerits of dry and wet process for the manufacture of Portland cement.

6M

b) Explain the classification of refractories with examples. 9M

Cont…2

:: 2 ::

Unit – IV

7. a) Explain the proximate analysis of coal along with its significance. 7M b) Describe the analysis of flue gas using Orsat’s apparatus.

8M

8. a) Give the advantages and disadvantages of solid, liquid and gaseous fuels. 8M b) A sample of coal was found to have the following percentage composition:

C=75%, H=5.2%, O=12.1%, N=3.2% and ash=4.5%. Calculate the weight and volume of minimum air required for complete combustion of 1Kg and 1m3 of coal.

7M

Unit – V

9. a) Define phase and component with examples. 5M b) Draw the phase diagram for Pb-Ag system, clearly indicating the eutectic point and

melting points of lead and silver. What is the phase rule applicable to such a system? Calculate the degree of freedom at the eutectic point.

10M

10. a) Write the applications of adsorption. 5M b) What are colloids? Discuss their optical and electrical properties. 10M




PROBABILITY THEORY AND NUMERICAL METHODS (Civil Engineering)



Unit – I

1. a) If the letters of the word ‘ENGINEERING’ be written at random, what is the probability that all the letters E are found together?

7M

b) A class has 10 boys and 5 girls. Three students are selected at random, one after the other. Find the probability that: i. First two are boys and third is a girl ii. First and third are boys and second is a girl iii. First and third are of same gender and the second is of opposite gender

8M

2. a) A bag contains 3 Red, 2 Green and 4 Yellow balls. A ball is drawn and if it is Red or Yellow it is replaced otherwise not. Find the probability that the second ball drawn is a Yellow ball.

7M

b) In a class 70 % are boys and 30 % are girls. 5 % of boys, 3 % of girls are irregular to the classes. What is the probability of a student selected at random is irregular to the classes and what is the probability that the irregular student is a girl?

8M

Unit – II

3. a) A random variable X has the following probability distribution.

X 1 2 3 4 5 6 7 8 P(X) k 2k 3k 4k 5k 6k 7k 8k

Find the value of (i) k (ii) 3P X (iii) 2 4P X

8M

b) Team A has probability 2/3 of winning whenever it plays. If A plays 4 games, find the probability that A wins: i. Exactly 2 games ii. At least 1 game iii. More than half of the games

7M

4. a) If the probability of a bad reaction from a certain injection is 0.002, determine the probability that out of 1000 individuals who had the injection: i. Exactly two will get a bad reaction ii. More than 3 will get a bad reaction

7M

b) Find the mean and S.D of a normal distribution in which 7 % of the items are under 35 and 89 % are under 63.

8M

Unit – III

5.

a) Apply Newton-Raphson method to find the real root of 3 0xe x 7M b) Construct the missing values in the following table:

x 0 5 10 15 20 25 y 6 10 - 17 - 31

8M

Cont…2

:: 2 ::

6. a) Using suitable interpolation formula, find the area A of a circle corresponding to the diameter D=98, given

D 80 85 90 95 100 A 5026 5674 6362 7088 7854

8M

b) If 1 3, 3 9, 4 30, 6 132y y y y then find 5y using Lagrange’s interpolation formula.

7M

Unit – IV

7. a) A function ( )y f x is given by the following table x 1 1.2 1.4 1.6 1.8 2.0 ( )f x 0.0 0.128 0.544 1.296 2.432 4.00

Find the approximate values of '(1.2)f and ''(1.2)f by using suitable interpolation formula.

8M

b) A solid of revolution is formed by rotating about the x-axis, the area between the x-axis, the lines 0x , 1x and a curve through the points with the following co-ordinates.

x 0 0.25 0.5 0.75 1 y 1 0.9896 0.9589 0.9089 0.8415

Estimate the volume of the solid formed using Simpson’s rule.

7M

8. a) If P is the pull required to lift a load W by means of a pulley block, find a linear law of the form P mW c by using the following data. Also find P when 150 .W Kg

P 12 15 21 25 W 50 70 100 120

8M

b) Evaluate

6

20 1

dxx by Simpson’s 3/8th rule taking seven ordinates.

7M

Unit – V

9.

a) Find by Taylor’s series method the value of y at 0.1x from 2 , (0) 1,dy x y ydx

(considering the terms up to the fourth degree).

6M

b) Given dy x ydx

with initial condition (0) 1y , find the approximate value of y at

0.2x , using modified Euler’s method. Perform three iterations.

9M

10.

a) Given 2 xdy e ydx

and (0) 2, (0.1) 2.010, (0.2) 2.040, (0.3) 2.090y y y y ,

evaluate (0.4)y by Adams-Bashforth method.

8M

b) Solve the initial value problem 2dy x ydx

with (0) 1y to find (0.1)y by Runge-Kutta

4th order method using step length 0.1h

7M




NUMERICAL METHODS (Common to Electronics and Communication Engineering & Mechanical Engineering)



Unit – I

1.

a) Find the real root of the equation 3 2 1 0x x using iteration method.

7M b) Solve the following using Jacobi’s iteration method.

10 2 92 20 2 44

2 3 10 22

x y zx y z

x y z

8M

2.

a) Obtain a root of sin 0x x correct to 4 decimal places using Newton-Raphson method.

7M b) Solve the following using Gauss-Seidel method.

83 11 4 957 52 13 1043 8 29 71

x y zx y zx y z

8M

Unit – II

3. a) Fit a polynomial of degree 2 which takes the following values:

x 0 1 2 3 4 y 1 1.8 1.3 2.5 2.3

7M

b) Apply Stirling’s formula to estimate 2.75f from the following data:

x 1 2 3 4 5

f x 1 -1 1 -1 1

8M

4.

a)

Using appropriate interpolation formula to compute sin 37o from the data given below:

x 15o 20o 25o 300 350

sin x 0.2588 0.342 0.4226 0.5 0.5736

7M

b) If 1 3y , 3 9y , 4 30y , 6 132y , find the Lagrange’s interpolation polynomial that takes on these values

8M

Cont…2

:: 2 ::

Unit – III

5. a) Find ' 2.2f and '' 2.2f given:

x 1.4 1.6 1.8 2.0 2.2 ( )f x 4.0552 4.9530 6.0496 7.3891 9.0250

8M

b) The voltage V across a capacitor at time t sec is given by the following table given below:

t 0 2 4 6 8 V 150 63 28 12 5.6

Use the method of least squares to fit a curve of the form ktV ae to this data.

7M

6.

a) Evaluate

6

20 1

dxx using Simpsons 3/8th rule.

7M

b) Fit a least square parabola to the following data:

x 0.0 0.2 0.4 0.7 0.9 1.0 y 1.016 0.768 0.648 0.401 0.272 0.193

8M

Unit – IV

7. a) Use Taylor’s series method to compute 0.2y for the differential equation

2 ; 0 1dy x y ydx

( considering the terms up to the fourth degree)

7M

b) Using Euler’s modified formula to find the value of y at x = 0.2 given that

10log ; 0 2dy x y ydx

8M

8. a) Obtain the Picard’s second approximation for the initial value problem

2

2 ; 0 01

dy x ydx y

. Find 1y .

7M

b) Using R-K method of fourth order , find 1.1y given that 23 ; 1 1.2dy x y y

dx

8M

Unit – V

9. Solve the Laplace equation 0xx yyu u for the figure given below with the boundary values as shown. Perform iteration only.

50 100 100 100 50

0 7u 8u 9u 0

0 4u 5u 6u 0

0 1u 2u 3u 0

0 0 0 0 0

15M

10. Solve the heat equation

2 2

22 , (0, ) 10, (6, ) 18, ( ,0)2

f f xf t f t f xt x

with 1h and

18

k by Schmidt explicit method for up to 58

t

15M




ELECTRONIC DEVICES AND CIRCUITS (Common to Computer Science and Engineering & Information Technology)



Unit – I

1. a) Sketch typical V-I characteristics of a PN junction. Explain the shape of V-I characteristics and compare with ideal diode characteristics.

8M

b) With neat diagrams explain Piecewise linear equivalent model of a diode.

7M

2. a) Write a neat block diagram of regulated power supply and explain each block briefly. 7M b) A 220 V, 50 Hz AC is applied to the primary of 5:1 step-up transformer with a tapped

secondary winding. The transformer along with a two-diode full-wave rectifier feeds a resistive load of 1000Ω. Determine:

i. DC power delivered to the load ii. Power rating of the transformer secondary iii. PIV across each diode iv. Ripple frequency and Ripple factor

8M

Unit – II

3. a) Sketch the common emitter circuit. Draw the input and output plots and thereby explain the active region, cut-off region and saturation region.

7M

b) With appropriate circuit, explain the operation of a common collector circuit.

8M

4. a) Sketch a block diagram to represent a n-channel FET. Indicate the voltage and current direction and also discuss the device operation.

7M

b) Explain the functioning of an enhancement mode MOSFET with appropriate graphs.

8M

Unit – III

5. a) Explain the factors that affect the thermal stability of a transistor. 7M b) Explain the concept of thermal runaway with appropriate diagram.

8M

6. a) Analyze the concept of fixed biasing in case of a FET with appropriate graphs and diagram.

7M

b) Discuss the process of voltage divider bias in case of a FET.

8M

Unit – IV

7. a) Derive the hybrid model for BJT in CB configuration. 7M b) Given that hybrid parameters for the transistor are hie=1.5kΩ, hfe=150, hre=1x10-4 and

hoe=20µmhos. Draw the hybrid equivalent circuit of the transistor in all three configurations.

8M

8. a) Perform quantitative comparison of CB, CE and CC amplifiers. 7M b) Obtain the expression for voltage gain and out impedance of BJT by its hybrid model.

Cont…2

8M

:: 2 ::

Unit – V

9. a) Explain the concept of negative feedback in series voltage feedback amplifiers. 7M b) Describe the classification of feedback amplifiers with appropriate sketch.

8M

10. a) Explain the working of a Hartley’s oscillator with appropriate circuit diagram. Also write the expression of the frequency of oscillations generated.

8M

b) In a colpitt’s oscillator, if the derived frequency is 800KHz, determine the values of inductor and capacitor. Also write its circuit diagram.

7M




ELECTRONIC DEVICES (Common to Electronics and Communication Engineering & Electrical and Electronics Engineering) Date: 24 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) In a pure or intrinsic semiconductor, explain the mechanism of conduction by electrons and holes.

7M

b) A bar of intrinsic silicon has a cross sectional area of 4 22.5 10 m . The electron density is 161.5 10 per 3m . How long the bar be in order that the current in the bar will be 1.2 mA when 9 V is applied across it. Assume 20.14 /nµ m V S

20.05 /pµ m V S .

8M

2. a) Explain how the conductivity of an intrinsic semiconductor is affected by temperature and light.

7M

b) The resistivity of pure silicon is 52.3 10 cm at 027 C . Calculate intrinsic concentration at 0127 C (Assume 20.14 /nµ m V S at 0300 K

20.05 /pµ m V S at 0300 K )

8M

Unit – II

3. a) Explain Zener and Avalanche breakdown mechanisms. 8M b) A silicon diode has reverse saturation current of 2.5 µA at 0300 K . Find the forward

voltage for a forward current of 10mA.

7M

4. a) Differentiate between transition capacitance and diffusion capacitance of a PN junction diode.

9M

b) The current flowing through a certain P-N junction at room temperature when reverse biased is 0.15 µA. Determine the current flowing through the diode when applied voltage is 0.12V.

6M

Unit – III

5. a) State and explain the characteristics of a Zener diode. How it can be used as a voltage regulator.

7M

b) Draw and explain the circuit diagram of a full-wave rectifier with shunt capacitor filter using two diodes and sketch the waveforms.

8M

6. a) Draw the V-I characteristics of tunnel diode. Explain its operation with necessary energy band diagrams.

8M

b) In a full-wave rectifier with capacitor filter, the load current from circuit operating from 200 V, 50Hz supply is 12 mA. Calculate minimum value of capacitor filter required to keep ripple voltage below 2%.

Cont…2

7M

::2::

Unit – IV

7. a) Draw the circuits of various transistor configurations. List their important features. Why CE configuration is mainly used? What are the uses of their configurations?

6M

b) Explain the construction and working of an UJT. List its applications.

9M

8. a) Explain the difference between enhancement mode and depletion mode MOSFETs. Sketch the cross sectional view of an enhancement mode MOSFET. Explain its operation with characteristics.

8M

b) Determine the value of emitter current and collector current of a transistor having dc = 0.98 and collector to base leakage current ICBO = 4 A. The base current is 50 A.

7M

Unit – V

9. a) A transistor is used in collector to base bias in CE configuration. If RC = 1K and VCC = 20 V, find the value of collector to base resistance such that VCE = 4 V. Assume VBE = 0, also determine stability factor in this case.

8M

b) A JFET amplifier with potential divider bias has device parameters VP = -2 V, IDSS = 5 mA, RD = 910, RS = 2.29 K , R1= 12 M , R2 = 8.57 M and VDD = 24 V. Find the value of ID at the operating point.

7M

10. a) A silicon transistor is used in the self biasing arrangement with VCC = 16 V and RC = 1.5 K. The operating point is chosen to be VCE = 8 V and IC = 4 mA. A stability factor S= 12 is desired if = 50. Find R1, R2 and RE.

8M

b) Design a self bias network using a JFET with IDSS = 8 mA and Vp = -6 V to have a Q-point at ID = 4 mA using a supply of 14 V. Assume RD = 3 RS and use standard values.

7M



B. Tech II Semester Regular Examinations, June - 2015 (Regulations: VCE-R14) BASIC ELECTRONICS

(Common to Mechanical Engineering & Civil Engineering) Date: 24 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) Draw and explain the V-I characteristics of a P-N junction. 7M b) With a circuit diagram, explain the working of a bridge rectifier. Give the input and

output waveforms.

8M

2. a) Explain the working of a Zener diode as a voltage regulator. 7M b) Derive the expressions for the following parameters of the half-wave rectifier circuit:

i. Ripple factor ii. Rectifier efficiency

8M

Unit – II

3. a) Draw and explain the input and output characteristics of a transistor in CE configuration and also indicate cut-off, saturation and active regions.

9M

b) Find the values of resistor RB, RC and RE and the transistor gain β, given that IB= 40μA, IC= 4mA, VE = 2V, VCE = 12V and supply voltage VCC =15v. Assume that the transistor used in the circuit is a silicon transistor.

Fig.1

6M

4. a) Explain the dc analysis for a collector-to-base bias configuration. 8M b) For the circuit diagram shown below in Fig.2 with Si transistor β = 50 is used. Draw the dc

load line & determine the operating point.

Fig.2

Cont..2

7M

:: 2 ::

Unit – III

5. a) Draw the hybrid model for a common-collector transistor and write the equations for input voltage and output current.

8M

b) The h-parameters for CE configuration are hie= 2600Ω, hfe = 100, hre= 0.02x102 and hoe = 5x10-6 S. Find h-parameters for CC configuration.

7M

6. a) Write short notes on transistor as an amplifier. 7M b) Compare the transistor configurations CB, CE and CC with respect to:

i. Input current ii. Output current iii. Current amplification factor iv. Current gain

8M

Unit – IV

7. a) Explain Barkhausen criterion. Illustrate the basic concept of positive feedback and negative feedback with relevant equations and block diagrams.

8M

b) Explain wein bridge oscillator and give expression for frequency.

7M

8. a) With a neat circuit diagram explain the function of RC phase shift oscillator. State the expression to calculate the frequency of oscillations.

8M

b) In a Colpitt’s oscillator, C1 = C2 = C and L= 100 μH. The frequency of oscillations is 500 KHZ. Determine the value of C.

7M

Unit – V

9. a) What are the basic properties of Boolean algebra? State and explain demorgan’s theorem.

7M

b) Convert: i. A4D6F16 to binary and octal ii. 1110.0011(2) to octal and decimal

8M

10. a) Show that NOR gates can realize OR, AND, NOT, NAND, EXOR gates. 9M b) Subtract 1100(2)-1010(2) from 2’s complement method. Compare the same with 1’s

complement method. 6M




DATA STRUCTURES THROUGH C (Common to Computer Science and Engineering, Information Technology, Electronics and

Communication Engineering & Electrical and Electronics Engineering) Date: 26 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) What is recursion? What are the two types of recursions? What are the contents of recursion?

8M

b) Write a algorithm to reverse the contents of a given array using recursion.

7M

2. a) Write a C program to search a given element using sequential and binary search. 10M b) Fibonacci numbers are defined recursively:

F0 = 0 F1 = 1 Fi = Fi-1 + Fi-2 for i > 1 Write a binary recursive algorithm for the same.

5M

Unit – II

3. a) Explain the radix sort technique by sorting the following sequence in ascending order. 60, 50, 25, 10, 35, 25, 75, 30, 85

5M

b) Give the algorithm for quick sort and merge sort techniques. Discuss which of the above two techniques is best in worst case by analyzing both.

10M

4. a) Compare selection sort and bubble sort technique. Sort the sequence 23, 12, 59, 85, 72 using the above two techniques and find the number of exchanges taken place.

10M

b) Compute the time analysis for insertion sort technique with the algorithm. 5M

Unit – III

5. a) Discuss the advantages of circular queue over linear queue. Write an algorithm to insert and delete an element from circular queue.

8M

b) Evaluate the following postfix expression and show the stack contents. AB + CD + *E / WITH A = 1, B = 2, C = 3, D = 4 & E = 5

7M

6. a) The following sequence of operations is performed on stack. PUSH A, PUSH B, PUSH C, POP, PUSH D, POP, POP, PUSH E, POP, POP. What is the sequence of popped elements?

5M

b) Discuss the representation of queue using arrays and write a program to implement linear queue.

10M

Unit – IV

7. a) Write an algorithm to create single linked lists. 8M b) Assume that you have been assigned task of deleting a sparse matrix. Write C function

for accomplish the same.

7M

8. a) What problem occurs when we insert a node to the front of a circular linked list? Suggest a possible solution for the same.

7M

b) Write a program to add two polynomials using single linked list. 8M

Cont…2

::2::

Unit - V 9. a) Give preorder, in-order and post order traversals for the following binary tree.

9M

b) Discuss the representation of graph using adjacency matrix and linked list.

6M

10. a) Discuss threaded binary tree with an example and give the advantages of the same. 7M b) Give the DFS and BFS traversals for the following graph with source vertex ‘a’.

8M

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