VARDHAMAN COLLEGE OF ENGINEERING...b) With neat sketch explain the Reverse Carnot refrigeration system with P-V and T-S graphs and derive COP of the Carnot refrigeration. 7M 2. a)

Hall Ticket No: Question Paper Code : A1015

VARDHAMAN COLLEGE OF ENGINEERING (AUTONOMOUS)

B. Tech VII Semester Supplementary Examinations, June - 2015 (Regulations: VCE-R11)

INDUSTRIAL MANAGEMENT AND PSYCHOLOGY (Electronics and Communication Engineering)

Date: 12 June, 2015 FN Time: 3 hours Max Marks: 75

Answer ONE question from each Unit All Questions Carry Equal Marks

Unit - I 1. a) Give a brief account of definition and concept of Management. 8M b) Write about the evolution and development of management thought.

7M

2. a) What is basic approach to Scientific Management? 8M b) List out and explain the functions of management. 7M

Unit – II 3. a) Mention different types of plant layouts. Explain any two of them. 8M b) Highlight the objectives of a good plant layout.

7M

4. a) Define work study. Explain the frame of work study. 8M b) Explain allowances with respect to work study. 7M

Unit – III 5. a) What are the rules and guidelines for drawing the network? 8M b) Explain about Project Evaluation and Review Technique (PERT).

7M

6. a) Define TQM. State and explain the primary elements of TQM 8M b) Explain ISO 9000 series procedure. State its advantages. 7M

Unit – IV 7. a) Discuss the functions of Human Resource Management in an organization. Enumerate the

challenges of HRM in the present organizational context. 8M

b) What is an Inventory Control System? Why it is Important?

7M

8. a) What is product life cycle? Briefly explain the stages involved in it. 8M b) Differentiate between marketing and sales. 7M

Unit – V 9. a) What are the aims and objectives of Industrial Psychology? How do you differentiate

Industrial Psychology and Personnel Management? 8M

b) Write about individual differences in behavior.

7M

10. a) Mention the four parts of Hawthorne experiments. On what factors The Hawthorne Experiments are mainly criticized.

8M

b) Analyze theory X type and theory Y type assumptions made for managers. 7M




REMOTE SENSING AND GIS APPLICATIONS (Civil Engineering)



Unit – I

1. a) Explain the concepts of electromagnetic remote sensing. 8M b) Explain the energy interaction in the atmosphere.

7M

2. a) List any five merits and limitations of remote sensing. 7M b) What are the elements to be considered during visual interpretation of satellite images?

8M

Unit – II

3. a) Define Photogrammetry? What are the uses of photogrammetry? 7M b) Explain parallax equation.

8M

4. a) What are the components involved in GIS? Explain about software components. 7M b) Explain about the following:

i. Kinds of mosaics ii. Stereoplotters

8M

Unit – III

5. a) Define the following terms: i. Instantaneous Field of View(IFOV) ii. Ground Resolution Element/Cell iii. False Colour Composite iv. Band pass filter

8M

b) Write short notes on the principle of operation of i. Whisk broom scanners ii. Push broom scanners

7M

6. a) What are the advantages and disadvantages of raster and vector data structure? 7M b) What are the types of basic computing file structure in GIS? Explain about simple list file

structure.

8M

Unit – IV

7. a) Describe Remote Sensing and GIS linkage and add a note on GIS Software. 8M b) Explain map projections and its importance. Explain the three basic families of map

projections.

7M

8. a) Write a note on the overview of the data manipulation and analysis. 8M b) Name the elements used for visual interpretation of remote sensing data. 7M

Cont…2

:: 2 ::

Unit – V

9. a) How the remote sensing is useful in Groundwater targeting and identification of sites for artificial recharge Structures.

8M

b) Write a note on applications of remote sensing approach for surface water management.

7M

10. a) How remote sensing applications are useful in flood and drought impact assessment and monitoring?

7M

b) Give an account on application of remote sensing and GIS for i. Land use/Land cover mapping ii. Drainage Morphometry

8M




POWER SYSTEM OPERATION AND CONTROL (Electrical and Electronics Engineering)



Unit – I

1. a) What are the constraints that the economic power system operation needs to satisfy? 7M b) The fuel cost function in Rs./hr for three thermal plants are given by:

C1=400+8.4P1+0.006P12

C2=600+8.93P2+0.0042P22

C3=650+6.78P3+0.004P32

Where P1, P2 and P3 are in MW. Neglecting line losses and generator limits, determine the optimal scheduling of generation of 550 MW loading.

8M

2. a) What is meant by loss coefficient matrix? Can the loss in transmission line be expressed in terms of real power generation? Explain by considering 2 units in the system.

7M

b) The IFC for two plants are: dc1/dPg1 = 0.075Pg1+18 Rs/MWhr dC2/dPg2 = 0.08Pg2 + 16 Rs/MWhr

The loss coefficient are given as B11 = 0.0015/MW, B12 = -0.0004/MW; and B22 = 0.0032/MW for lambda = 25 Rs./MWH. Find the real power generation, total demand and the transmission power loss.

8M

Unit – II

3. a) What are the scheduling methods for short term hydro thermal coordination? 7M b) What is the condition for optimality in the case of a hydro-thermal scheduling problem?

If this condition is violated, how will we obtain optimality?

8M

4. a) What are the advantages of operation of hydro thermal combinations? 7M b) What are the important methods for short term hydro-thermal co-ordination?

8M

Unit – III

5. a) Describe the four main components of a speed governing system. 7M b) Obtain the first order turbine model.

8M

6. a) Two alternators rated 100MW and 200MW have a governor droop characteristics of 4% from no load to full load. They are connected in parallel to share a load of 250MW. Determine the load shared by each machine.

7M

b) Draw the IEEE Type I excitation model and explain each block in brief.

8M

Cont…2

:: 2 ::

Unit – IV

7. a) Obtain the dynamic response of an isolated power system with constant load demand with variable speed-changer position (controlled case).

7M

b) An isolated control area consists of a 200MW generator with an inertia constant of H=5KW-sec/KVA having the following parameters Power system gain constant = 100; Power system time constant = 20sec. Speed regulation = 3; Normal frequency = 50 Hz; Governor time constant = 0.4 sec Turbine time constant = 0.5sec. Obtain the frequency error and plot the graph of deviation of frequency when a step change of 1% in the speed changer position is applied.

8M

8. a) Discuss the importance of combined load frequency control and economic dispatch control with a neat block diagram.

7M

b) Obtain the static response of a two area system – uncontrolled case.

8M

Unit – V

9. a) What are the characteristics of an ideal compensator? 7M b) A 400V 50Hz 3 phase supply delivers 200KW at 0.7 pf lagging. It is desired to bring the line

pf to 0.9 by installing shunt capacitors.

Calculate the capacitance if they are star connected.

8M

10. a) Explain briefly the effect of series and shunt compensation of transmission lines. 7M b) A three phase 500hp 50Hz 11KV star connected induction motor has a full load efficiency

of 85% at lagging pf of 0.75 and is connected to a feeder. if the pf of load is desired to be corrected to 0.9 lagging, determine the size of the capacitor bank and capacitance of each unit if the capacitance is connected in delta.

8M




REFRIGERATION AND AIR CONDITIONING (Mechanical Engineering)



Unit – I

1. a) Briefly discuss the following with refrigeration:

i. Unit of refrigeration ii. COP iii. Relative COP iv. Energy Performance Ratio

8M

b) With neat sketch explain the Reverse Carnot refrigeration system with P-V and T-S graphs and derive COP of the Carnot refrigeration.

7M

2. a) Illustrate the Comparison of Reverse Carnot and reverse Brayton cycle in T-S graph. 7M b) i. Why in an aircraft, cooling systems are required to keep the cabin temperatures at a

comfortable level. Even though the outside temperatures are very low at high altitudes, still cooling of cabin is required?

8M

ii. Even though the COP of air cycle refrigeration is very low compared to vapor compression refrigeration systems, it is still found to be most suitable for aircraft. Refrigeration system why?

Unit – II

3. a) Derive the expression for COP from T-S chart for a vapour compression refrigeration system.

7M

b) In a trial of a refrigerator, the HP impressed on CO2 compressor is 1.6. The circulating brine in the evaporator lost 70 KCal/min. and cooling water took away 140Kcal/min from condenser coil. Find out the actual COP of the system. If the temperatures are 16.650C and 00C and their corresponding latent heats are 40.9 and 55.5KCal/kg and difference between the liquid energy is 8.9Kcal/kg, find out the relative COP assuming that the vapour is just dry and saturated at the end of compression.

8M

4. a) List the components and explain the working principle of a two shell Li-Br vapour absorption system.

8M

b) In an absorption refrigeration system, heating, cooling and refrigeration takes place at the temperatures of 1500C, 300C and -200C. Find out the theoretical COP of the system. If the heating temperature is increased to 2000C and refrigeration temperature is decreased to -400C, find out the percentage in theoretical COP.

7M

Unit – III

5. a) With neat sketch explain the working principle of a capillary tube and state its advantages and disadvantages.

8M

b) Explain the working principle of a forced convection evaporator.

Cont…2

7M

:: 2 ::

6. a) What are the functions of expansion devices? List all the expansion devices used in refrigerating system.

7M

b) Briefly discuss with neat sketch the working principle of thermo electric refrigeration system.

8M

Unit – IV

7. a) Define psychrometry and atmospheric air. List the important psychrometric properties. 7M b) An air conditioned space is maintained at 26oC DBT 50%RH. When the outdoor conditions

are 35oC DBT and 28oc WBT, the space has a sensible heat gain of 17.6KW and the air to the space is supplied at a condition of 8oC saturated, determine: i. The mass and volume flow rate of the air supplied ii. Latent heat load in the room iii. The cooling load of the refrigerator plant if 15% of the total weight of air supplied to the space is fresh air and the remaining air is re circulated.

8M

8. a) Briefly discuss the following: i. ESHP ii. RSHP iii. GSHF iv. ADP

7M

b) An air conditioned space is maintained at 270C DBT 50% RH. The ambient conditions are 400C DBT and 270C WBT. The space has a sensible heat gain of 14KW. Air is supplied to the space at 70C saturated. Calculate i. Mass of moist air supplied to the space in kg/h ii. Latent heat gain of space in KW iii. Cooling load of the air washer in KW if 30% of the air supplied to the space is fresh,

the remainder being recirculated.

8M

Unit – V

9. a) Briefly discuss the Selection criteria for air conditioning systems. 7M b) What is human comfort? List and discus the factors that affect humans pleasantly or

adversely.

8M

10. a) Why fan is required in air conditioning system? Define fan law and important operating parameters of fans.

9M

b) A fan is designed to operate at a rotative speed of 20 rps. At the design conditions the airflow rate is 20m3/s, the static pressure rise is 30 Pa and the air temperature is 20oC. At these conditions the fan requires a power input of 1.5 kW. Keeping the speed constant at 20 rps, if the air temperature changes to 10oC, what will be the airflow rate, static pressure and power input?

6M



B. Tech VII Semester Supplementary Examinations, June - 2015 (Regulations: VCE-R11) IMAGE PROCESSING

(Computer Science and Engineering) Date: 23 June, 2015 FN Time: 3 hours Max Marks: 75


Unit – I

1. a) Briefly describe Image representation. 7M b) Consider the image segment shown. Let V= 1 and compute the length of the shortest 4,

8 and m-path between p and q. If a particular path exists between these two points, explain why?

S1 S2 0 0 0 0 0 0 0 1 q:1

0 1 0 0 1 0 0 1 0 0 1 1 0 0 1 0 1 1 0 0 0 0 0 p:1

1 1 0 0 1 1 1 0 0 1 1 1 0 0 1 1 1

8M

2. a) Discuss the following properties of 2D Fourier Transform: i. Separable ii. Convolution and correlation iii. Conjugate Symmetry and periodicity

9M

b) Write a short note on 2D-DCT. 6M

Unit – II

3. a) Explain the basics of spatial filtering in detail. 7M b) Define histogram. Discuss histogram processing in detail.

8M

4. a) With a neat block diagram, explain homomorphic filtering approach in detail. 10M b) Discuss sharpening spatial filters in detail.

5M

Unit – III

5. a) Explain the following terms: i. Coding redundancy ii. Psychovisual redundancy iii. Variable length coding

6M

b) Explain Lossless predictive coding.

9M

6. a) Discuss the basics of transform coding. 5M b) With the help of block diagram explain JPEG Encoder.

10M

Unit – IV

7. a) Explain the basic formulation of edge modeling and detection. 7M b) Discuss the Laplacian used in edge detection.

8M

8. a) Explain the watershed algorithm used in segmentation. 10M b) Write a short note on use of motion in segmentation.

5M

Cont…2

::2::

Unit – V

9. a) With a neat block diagram explain the concept of color image compression. 6M b) Explain color image smoothing and sharpening.

9M

10. a) Define dilation and erosion. 5M b) Explain the morphological algorithm for region filling. 10M




POWER SYSTEM SWITCHGEAR AND PROTECTION (Electrical and Electronics Engineering)



Unit – I

1. a) Derive an expression for Restriking Voltage and Rate of Rise of Restriking Voltage (RRRV). 10M b) A circuit breaker interrupts the magnetizing of a 100 MVA transformer at 220kV. The

magnetizing current of the transformer is 5% of the full load current. Determine the maximum voltage which may appear across the gap of the breaker when the magnetizing current is interrupted at 53% of its peak value. The stray capacitance is 2500F. The inductance is 30H.

5M

2. a) List out the advantages and disadvantages of air blast circuit breaker over oil circuit breaker.

8M

b) With a neat sketch explain the working of plain-break oil circuit breaker.

7M

Unit – II

3. a) Briefly explain the fundamental requirements of protective relaying. 7M b) Explain with the neat diagram construction and principle of operation of attracted

armature type relay.

8M

4. a) Derive an expression for the net force developed in an electromagnetic induction relay. 7M b) List out the merits and demerits of static relays.

8M

Unit – III

5. a) What is the principle of operation of Bucholtz relay? Where is it located? Briefly explain its working.

8M

b) What are the various types of faults that can occur on an alternator? Explain briefly.

7M

6. a) Describe with a neat sketch, the percentage differential protection for Y - connected transformer.

8M

b) A 10 MVA, 6.6 kV, 3 phase star connected alternator is protected by Merz-Price circulating current system. If the ratio of the current transformer is 1000/5, the minimum operating current for the relay is 0.75 A and the neutral point earthing resistance is 6, calculate: i. The percentage of each of the stator windings which is unprotected against earth

faults when the machine is operating at normal voltage ii. The minimum resistance to provide protection for 90% of thee stator winding.

7M

Unit – IV

7. a) Discuss different types of power system transients. 6M b) Explain briefly repeated reflections using Bewley’s Lattice diagrams.

Cont…2

9M

:: 2 ::

8. a) Explain the variation of I and V on overhead line when one end of the line is short circuited line.

7M

b) A steep fronted wave travelling in a line of surge impedance Z1 meets at a point P a surge impedance Z2. Derive the expressions for transmitted and reflected voltages and currents beyond the point P. Using the expression, interpret the following situations: i. A surge meets, a sub-station, an opened out isolator. ii. A surge meets a sub-station from where 2 more lines are taken out.

8M

Unit – V

9. a) List the advantages and disadvantages of grounding the neutral point using solid grounding method.

7M

b) What is lightning? Describe the mechanism of lightning discharge. Also discuss the different types of lightning strokes.

8M

10. Write short notes on any three of the following: i. Ungrounded neutral system ii. Resonant grounding iii. Zinc oxide lightning arrester iv. Earthing screen protection against direct lightning strokes

15M




INSTRUMENTATION AND CONTROL SYSTEMS (Mechanical Engineering)



Unit - I 1. a) Differentiate between static and dynamic performance characteristics. 7M b) Write a brief note on photo electric transducers.

8M

2. a) Write a brief note on the sources of error and their classification. 8M b) Explain the principle of operation of an inductive transducer. 7M

Unit – II 3. a) Explain how pressure is measured using McLeod pressure gauge. 7M b) With a neat diagram explain the construction and working of a magnetic flow

meter.

8M

4. a) A monometer is to use transfer oil of relative density 0.80 as the monometric liquid, but the scale is to graduated in millimeters of water. If one leg is 2mm bore tube and the other is 20 mm diameter well, calculate the angle to the horizontal at which the tube and scale must be inclined to give 5mm scale deflection for a pressure difference equivalent of 1mm head of water.

7M

b) Explain the various methods and devices for fluid flow measurements used in various Engineering Applications.

8M

Unit – III 5. a) Write a brief note on Non contact type tachometer. 8M b) Explain how acceleration can be measured.

7M

6. a) Compare and contrast AC tachometer generator versus photo tachometer generator used for measurement of angular velocity.

8M

b) Explain the principles of Siesmic Instruments. 7M

Unit – IV 7. a) Explain the usage of Wheatstone bridge for strain measurement. 8M b) Write a brief note on temperature indicators.

7M

8. a) Discuss resistance strain gauge. Derive the relationship for relating resistance change and strain.

7M

b) Explain the Laws of thermocouples used for measurement of temperature. 8M

Cont…2

::2::

Unit – V 9. a) With examples explain Open and closed loop system. 7M b) Explain the following important term with respect to measurement of humidity:

i. Moist air and saturated air ii. Absolute humidity iii. Wet bulb temperature

8M

10. a) Explain servomechanism, process control and regulators. 7M b) With examples explain Manual operated and Automatic control systems. 8M




EMBEDDED SYSTEMS (Common to Electrical and Electronics Engineering & Electronics and Communication Engineering) Date: 16 June, 2015 FN Time: 3 hours Max Marks: 75

Answer ONE question from each Unit

All Questions Carry Equal Marks

Unit – I

1. a) Explain the importance of design methodology in Embedded Systems. Illustrate the major steps in the Embedded System Design process along with a neat figure showing all the major levels of abstraction in the design process.

10M

b) Explain the features and functionalities of UML.

5M

2. a) Explain how the behavior of the system can be specified in the design of embedded systems. List the three types of Events defined by UML and Illustrate how state machine specification is implemented in UML with example.

10M

b) Explain the Model train control system with a neat figure. 5M

Unit – II

3. a) Explain the memory organization in 8051 microcontroller with the help of a neat figure. 8M b) Discuss the different serial communication modes and its functionalities in 8051

microcontroller.

7M

4. a) Explain the three Unconditional jump instructions – LJMP, SJMP and AJMP with relevant instruction set showing their ranges and examples.

8M

b) i) Write an assembly level language program to add ‘N’ BCD numbers, numbers are stored at location starting from 40H.

7M

ii) Illustrate the operation of PUSH and POP instructions with examples.

Unit – III

5. a) What is a task? Explain different states of tasks. Discuss the operation of schedular. 7M b) Explain Events and its standard features. Briefly Compare different methods used for

intertask communication. 8M

6. a) Explain Interrupt routines in an RTOS environment. 8M b) Explain the problems that occur when semaphore is used in embedded system design. 7M

Unit – IV

7. a) Explain briefly different methods of placing embedded software into the target system. 8M b) Explain script file and output file used of testing embedded software on host with an

example. 7M

8. a) Write a short note on: i. Address Resolution ii. Initialized data and constant strings iii. Locator Maps

9M

b) Mention the goals of the typical testing process. Explain the basic method for testing embedded software on the development host with a neat diagram.

6M

Cont…2

:: 2 ::

Unit – V

9. a) Demonstrate the Register Indirect and Absolute addressing in ARM using an example. 6M b) i) Illustrate the basic SHARC programming model showing all the Registers. 9M ii) Explain how parallelism within instructions is implemented in SHARC.

10. a) Describe the feature, data frame formats and architecture of a CAN controller with a neat figure.

8M

b) Describe the theory of operation for an Elevator controller with a neat figure and identify the various requirements to design the Elevator controller.

7M




OPERATING SYSTEMS (Electronics and Communication Engineering)



Unit – I

1. a) What are distributed systems? Explain in detail. 6M b) Explain the various services provided by an operating system.

9M

2. a) What are system programs? Explain various types of system programs in detail. 8M b) Explain the structure of UNIX operating system in detail.

7M

Unit – II

3. a) Explain Peterson's solution to critical-section problem. 7M b) Explain readers-writers problem in detail.

8M

4. a) Explain the necessary conditions for a deadlock to occur. 7M b) Explain the two options for breaking a deadlock in detail.

8M

Unit – III

5. a) What are the activities of an operating system with regard to process management and file management?

5M

b) Consider the following reference string: 7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1 Assuming three frames, all initially empty how many page faults would occur for:

i. LRU ii. FIFO iii. Optimal page replacement algorithms? Which of the algorithm is most efficient

in this case?

10M

6. a) Considering an example with supporting diagrams, explain linked and indexed method of allocating disk space.

8M

b) Write neat diagram of any three directory structures.

7M

Unit – IV

7. a) Mention the three important aspects of tertiary-storage performance. Explain any one briefly.

3M

b) A disk drive has 200 cylinders numbered from 0 to 199. The disk head is initially at cylinder 53. The queue of pending requests in FIFO order is: 98, 183, 37, 122, 14, 124, 65, 67. Starting from the current head position, what is the total distance traveled (in cylinders) by the disk arm to satisfy the requests using algorithms FCFS, SSTF, SCAN and LOOK. Illustrate with figures in each case.

Cont…2

12M

:: 2 ::

8. a) Write a short note on: i. STREAMS ii. Direct Memory Access iii. Kernel I/O structure

9M

b) Define: i. Cache ii. Spooling iii. Buffer

6M

Unit – V

9. a) Describe the access matrix model used for protection in operating systems. 7M b) Write short note on:

i. Access control ii. Revocation of Access Rights

8M

10. a) Discuss the use of passwords as a mechanism for ensuring user authentication in operating system security.

8M

b) Explain boot-sector computer virus. 7M




SOFTWARE TESTING AND QUALITY ASSURANCE (Common to Computer Science and Engineering & Information Technology)



Unit - I 1. a) What should testing and test design focus on? Explain. 8M b) Differentiate between flowgraphs and flowcharts.

7M

2. a) Discuss the concept of unit, component and system testing. 10M b) How testing is different from debugging process? Discuss why testing is to be done for a

program? 5M

Unit – II 3. a) Discuss the steps in conducting transaction flow walkthroughs. 8M b) Describe the concept of domain dimensionality.

7M

4. a) Why isn’t static analysis enough to detect anomalies? Explain. 10M b) Define interior, boundary and extreme points. 5M

Unit – III 5. a) Discuss with an example how the maximum path count is possible in a flow graph. 8M b) Write a short note on decision table testing method.

7M

6. a) Reduce the following function using K-Maps. F(A,B,C,D)=P(1,2,4,5,6,7,8,12,13)+D(1,15)

8M

b) Explain identity elements and absorption laws. 7M

Unit – IV 7. a) What constitutes a good or a bad state graph? 6M b) Explain briefly transitive, reflexive and symmetric relations with an example.

9M

8. Explain node reduction algorithm along with a suitable example. 15M

Unit – V 9. a) Explain regression testing. 10M b) What is data driven testing?

5M

10. How win runner and QTP are used for functional testing? Explain. 15M




POWER SEMICONDUCTOR DRIVES (Electrical and Electronics Engineering)



Unit – I

1. a) Derive the expressions relating speed and torque of a dc series motor and thereby plot its characteristics.

7M

b) A 220V, 600rpm, 500A separately excited DC motor has armature and field resistances of 0.02Ω and 10Ω respectively. Armature is fed from a three-phase fully-controlled rectifier and field from half-controlled single-phase rectifier. A three-wire three-phase ac source with a line voltage of 440V is available. Armature rectifier is fed from a three-phase transformer with star-delta connection and field-rectifier from a single-phase transformer. Calculate the firing angles of the armature rectifier for: i. Rated torque and field and 400rpm ii. Rated torque and field, and -400rpm iii. Assume continuous conduction

8M

2. a) With suitable diagram, Explain the operation of a single phase fully-controlled converter fed separately excited DC motor in continuous current conduction mode.

8M

b) A 220V, 750rpm, 200A separately excited motor has armature and field resistance of 0.05Ω and 20Ω, respectively. Load torque is given by the expression TL = 500 – 0.2N Nm, where N is the speed in rpm. Speeds below rated value are obtained by armature voltage control and speeds above rated value are obtained by field control. Armature is fed from a three phase fully-controlled rectifier with ac source voltage (line) of 170V, 50Hz and the field is fed from a half-controlled single-phase rectifier with a single-phase source voltage of 250V, 50Hz. Drive operates under continuous conduction. Calculate firing angles for speeds: i. 600rpm ii. 1200rpm

7M

Unit – II

3. a) Describe the working of a dual converter control of dc separately excited motor, including the procedure for speed reversal

7M

b) A 220V, 20kW dc shunt motor running at its rated speed of 1200 rpm is to be braked by reverse current braking. The armature resistance is 0.1 Ohm and the rated efficiency of the motor is 88%. Calculate: i. Resistance to be connected in series with the armature to limit the initial braking

current to twice the rated current ii. The initial braking torque iii. The torque when the speed of the motor falls to 400 rpm.

Cont….2

8M

::2::

4. a) With a neat circuit diagram and relevant equations , explain the operation of chopper control of separately excited motor , for regenerative braking

5M

b) A 230V, 1200 rpm, 15A, separately excited dc motor has an armature resistance of 1.2Ω. Motor is operated under dynamic braking with chopper control. Braking resistance has a value of 20Ω. Calculate: i. Duty ratio of chopper for motor speed of 1000 rpm and braking torque equal to 1.5

times rated motor torque ii. What will be the motor speed for duty ratio of 0.5 and motor torque equal to its

rated torque

10M

Unit – III

5. a) Explain the theory behind braking operation of voltage source inverter fed induction motors.

7M

b) A 2.8kW, 400V, 50Hz, 4-pole, 1370rpm, delta connected squirrel-cage induction motor has following parameters referred to the stator: Rs = 2Ω, Rr’= 5Ω, Xs = Xr’= 5Ω, Xm= 80Ω. Motor speed is controlled by stator voltage control. When driving a fan load it runs at rated speed at rated voltage. Calculate motor terminal voltage, current and torque at 1200rpm.

8M

6. a) List out the advantages and features of cyclo converter controlled induction motor drive and also draw the block diagram for a closed- loop slip controlled PWM inverter drive.

7M

b) A star connected squirrel cage induction motor has the following ratings and parameters: 400V, 50Hz, 4-pole, 1370 rpm, Rs = 2Ω, Rr’= 3Ω, Xs = Xr’ = 3.5Ω. Motor is controlled by a voltage source inverter at constant V/f ratio. Inverter allows frequency variation from 10 to 50Hz. Calculate starting torque and current of the drive as a ratio of their values when motor is started at rated voltage and frequency.

8M

Unit – IV

7. a) What do you mean by slip power recovery scheme for controlling the speed of a induction motor.

5M

b) A three phase 400V, 50Hz, 6-pole, 960 rpm, star connected wound rotor induction motor has the following constants referred to the stator. R1= 0.5 Ω, R2

’= 0.7Ω, X1=X2’=1.5Ω. The motor drives a fan load at 960 rpm. The stator to

rotor turns ratio is 2. Calculate the resistance required to be connected in each phase of the rotor circuit to reduce the speed to 600 rpm.

10M

8. a) Why has the static Kramer drive a low range of speed control? Draw the constant torque drive and constant horse power drive for Kramer control.

9M

b) Explain with speed torque characteristics the operation of induction motor with addition of balanced resistors in rotor circuit.

6M

Unit – V

9. a) With a neat diagram explain the operation of a self controlled synchronous motor drive employing load commutated inverter.

7M

b) A 20 kW 3 phase, 440V, 4 pole delta connected permanent magnet synchronous motor has the following parameters: Xs= 5Ω , Rs=negligible, rated p.f.=1.0 machine is controlled by variable frequency control at a constant (V/f) ratio. Calculate armature current, torque angle and power factor at half full load torque and 750 rpm.

8M

10. a) Draw the block diagram for the closed loop speed control of load commutated inverter synchronous motor drive

7M

b) i. What are the advantages and applications of synchronous motor drive employing load commutated inverter?

ii. Why a self controlled synchronous motor is free from hunting?

8M




CELLULAR AND MOBILE COMMUNICATIONS (Electronics and Communication Engineering)



Unit – I

1. a) Explain the three categories and their features for specifying the performance criteria in cellular system.

7M

b) Explain the operation of cellular system.

8M

2. a) What is co-channel interference? Show that co-channel Interference of 18dB can be achieved with 7 cell cluster.

7M

b) Sketch a neat figure showing the general view of the cellular telecommunication system and explain the various considerations of the components of cellular systems.

8M

Unit – II

3. a) Compare the co-channel interference performance of a directional antenna system for k =7 and k=4 cell patterns.

8M

b) Illustrate how the parasitic elements help in interference reduction and the ways of combining a driven antenna and a single parasite.

7M

4. a) Explain the different measurements of SINAD. 7M b) Explain the interference between systems in scenarios of one city and adjacent cities and

how it can be reduced?

8M

Unit – III

5. a) With relevant diagrams, explain the concept of path-loss phenomenon. 7M b) Explain the situations under which omni-directional antennas are used at cell site.

8M

6. a) Enumerate the expression for Sum-and-Difference patterns of antenna. Also explain the different synthesis methods of Sum-and-Difference patterns used to generate a desired antenna configuration.

10M

b) Explain the patterns of any two Mobile antennas. 5M

Unit – IV

7. a) List the different techniques for increasing the frequency spectrum in cellular mobile radio system.

7M

b) What is handoff? Explain the different types of handoff schemes.

8M

8. a) Explain the concept of adjacent – channel assignment. 7M b) Briefly explain the following handoff schemes:

i. Mobile assisted handoff ii. Soft handoff

8M

Cont…2

::2::

Unit – V

9. a) With a neat block diagram, explain the NA – TDMA system architecture. 8M b) Explain the different kinds of channels in Downlink common channels.

7M

10. a) Write a note on the following network entities of the GSM system: i. Home Location register ii. Visitor location register iii. Gateway MSC

8M

b) Explain the need for and different kinds of link protocol in radio resource management. 7M




OPERATIONS RESEARCH (Common to Information Technology & Mechanical Engineering)



Unit – I 1. Solve the following problem using simplex method.

Max. Z = 1850x1 + 2080x2 + 1875x3 Subject to, x1 + x2 + x3 100 5x1 + 6x2 + 5x3 400 x1, x2, x3 0

15M

2. a) With a neat flow diagram explain the phases followed in OR study 6M b) Solve the following LPP using Big M method.

Maximize, Z = 3x1 +2x2 Subject to, 2x1 + x2 ≤ 2 3x1+ 4x2 ≥ 12 x1, x2 ≥ 0

9M

Unit – II

3. a) What is an assignment problem? 2M b) Consider the problem of transporting a product from three sources to four destinations.

The distance between sources and destinations as well as the supply and demand units are given in the following table. The transportation cost is proportional to distance. Find the optimum transportation schedule for the product.

To From D1 D2 D3 D4 Capacity

O1 5 10 15 9 15 O2 5 15 7 8 30 O3 10 7 6 4 30

Requirement 10 20 15 30

13M

4. a) A department head has four sub ordinates and four tasks have to be performed. Subordinates differ in efficiency and tasks differ in their intrinsic difficulty. Time each man would take to perform each task is given in the effectiveness matrix. How the tasks should be allocated to each person so as to minimize the total man hours.

I II III IV A 8 26 17 11 B 13 28 4 26 C 38 19 18 15 D 19 26 24 10

7M

b) Five men are available to do five different jobs. From past records, the time ( in hours) that each man takes to do each job is known and given in the following table:

I II III IV V A 2 9 2 7 1 B 6 8 7 6 1 C 4 6 5 3 1 D 4 2 7 3 1 E 5 3 9 5 1

8M

::2::

Unit – III 5. There are five jobs, each of which must go through the two machines A and B in the order AB.

Processing times are given in the table below. Determine a sequence for five jobs that will minimize the total elapsed time. Calculate the total idle time for the machines in this period.

Job 1 2 3 4 5 Time for A 5 1 9 3 10 Time for B 2 6 7 8 4

15M

6. a) List the applications, advantages and disadvantages of queuing models 6M b) A road transportation company has one reservation clerk on duty at a time. She handles

information of bus schedules and makes reservations. Customers arrive at a rate of 8 per hour and the clerk can serve 12 customers on an average per hour. Calculate the following: i. What is the average number of customers waiting for the service of the clerk? ii. What is the average time a customer has to wait before getting service? iii. The management is contemplating to install a computer system to handle the

information and reservations. This is expected to reduce the service time from 5 to 3 minutes. The additional cost of having the new system works out to be 12 paise per minute spent waiting before being served, should the company install the computer system. Assume 8 hour working day.

9M

Unit – IV

7. An electronic equipment contains 500 resistors. When any resistor fails it is replaced. The cost

of replacing a resistor individually is Rs. 20. If all the resistors are replaced at the same time, the cost per resistor is Rs.5. The percentage surviving at the end of the month is given below. What is the optimum replacement plan?

Month 0 1 2 3 4 5 S 100 90 75 55 30 0

15M

8. a) A stockiest has to supply 400 units of a product every Monday to his customers. He gets the product at Rs. 50 per unit from the manufacturer. The cost of ordering and transportation from the manufacturer is Rs. 75 per order. The cost of carrying inventory is 7.5% per year of the cost of the product. Find i. The economic lot size ii. The total optimum cost ( including capital cost)

7M

b) A company has a demand of 12000 units per year for an item and it can produce 2000 such items per month. The cost of one set up is Rs. 400 and the holding cost/unit/month is Rs. 0.15. Find the optimum lot size and the total cost per year, assuming the cost of 1 unit is Rs. 4. Also find the maximum inventory, manufacturing time and the total time.

8M

Unit – V

9. a) Explain the principle and rules of dominance to reduce the size of the pay off matrix. 7M b) Solve the following game by graphical method:

I II I 2 4 II 2 3 III 3 2 IV -2 6

8M

10. Explain the characteristics of dynamic programming problems. Explain dynamic programming with an example.

15M




CPLD AND FPGA ARCHITECTURES AND APPLICATIONS (Electronics and Communication Engineering)



Unit – I

1. a) With a neat flow diagram, Explain the abstractions for FPGA Design. 8M b) Explain the concept of Hierarchical Logic Design with example.

7M

2. Explain: i. Programmable sum of Product Array ii. PAL Fuse matrix iii. FPGA Programming

15M

Unit – II

3. a) With a flow-chart explain the Methodology for evaluating FPGA Fabrics. 8M b) What are the features of I/O pins? Draw the schematic for Xilinx Spartan-II I/O block?

7M

4. a) What are the advantages and disadvantages in SRAM-Based FPGAs? 7M b) Explain Logic Element cluster and what are the factors involved in logic element design.

8M

Unit – III

5. a) With a neat block diagram, explain the organization of Carry skip adder. 7M b) Write the verilog code for 8 bit carry skip adder.

8M

6. a) With appropriate example, explain how retiming preserves the combinational function? 6M b) What is clock skew? Explain how the effect of clock skew can be minimized in a physical

design?

9M

Unit – IV

7. a) Explain: i. Simplification ii. Network restructuring iii. Delay restructuring

6M

b) Draw the schematics (using AND, OR and NOT gates) that represent the results of syntax-directed translation of these statements. i. a & (b|c) ii. if (e) then x=a else x=b; iii. if (e) then x <=a or b; else x<=a and not b;

9M

8. Explain: i. Placement by clustering ii. Placement by partitioning iii. Logic synthesis

15M

Cont…2

:: 2 ::

Unit – V

9. a) Design a Mealy FSM that has an input ‘w’ and an output ‘z’. The machine is a sequence detector that produces z=’1’ if during two immediately preceding clock cycles the input ‘w’ was equal to ‘1’ otherwise the value of ‘z’ is equal to ‘0’ and also write the verilog code for the same.

12M

b) Explain One hot Encoding.

3M

10. a) Briefly explain the Global and detailed routing. 5M b) Explain the following:

i. Logic Synthesis ii. Logic Implementation by Macro

10M

Documents

VARDHAMAN COLLEGE OF ENGINEERING...b) With neat sketch explain the Reverse Carnot refrigeration system with P-V and T-S graphs and derive COP of the Carnot refrigeration. 7M 2. a)