Anna University Coimbatore 2011 B.E Electrical and Electronics Engineering Computer architecture - Question Paper
computer architecture(CA),power electronics(PE),power system analysis and stability(PSAS),Digital signal processing(DSP)
ANNA UNIVERSITY OF TECHNOLOGY, COIMBATORE B.E. I B.TECH. DEGREE EXAMINATIONS : APRIL / MAY 2011 REGULATIONS : 2008 SIXTH SEMESTER - EEE
080280056 - COMPUTER ARCHITECTURE Time : 3 Hours Max.Marks : 100
PART- A
ANSWER ALL QUESTIONS
1. Give the IEEE standard single precision and double precision Floating point representation
2. What are the different stages of instruction execution?
3. What is the difference between arithmetic shift and logical shift?
4. Design a 4-bit combinational circuit decrementer using 4 FAs
5. What are the differences between Hardwired control unit and Micro programmed control unit?
6. Give the microinstruction code format and explain its fields..
7. Convert the following expression in to Reverse polish notation A*B +C*D
8. What are one address and two address instructions .Give examples for each?
9. Define pipelining
10. Define the efficiency of a linear pipeline processor.
11. Give the Booth's recording of the number 11000
12. What is biased exponent?
13. What is the basic advantage of using interrupt initiated data transfer over transfer under program control with out an interrupt
14. Why does the DMA gets priority over CPU when both request memory transfer.
15. Differentiate synchronous and asynchronous communication.
16. Define Baud rate
17. What is associative memory?
18. i. How many 128x8 RAM chips are needed to provide a memory
capacity of 2048 bytes?
ii. How many lines of address bus must be used to access 2048 bytes of memory. How many of these lines will be common to all chips?
19. What is Virtual Memory?
20. In many computers the cache block size is in the range of 32 to 128 bytes.
What would be main advantage of making the size of the cache blocks larger or smaller
PART -B
(5 x 12 = 60 MARKS)
ANSWER ANY FIVE QUESTIONS
21. a With a neat block diagram explain the architecture of a basic 8
computer
b Write a note on memory reference instructions 4
22. a Explain with a neat block diagram the different ways of generating 8
the next address of the microinstruction using microprogram sequencer.
b Write short notes on stack organization 4
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23. a Explain different addressing modes with an example.
b Write the characteristics of Reduced Instruction Set Computer
24. With a neat flow chart explain the Booths Multiplication algorithm. Multiply (-9 ) x (-13) using booths multiplication algorithm.
25. a Explain the concept of linear pipelining . Derive the expression for
speedup ratio
b What are the types of pipeline hazards (pipeline conflicts )
26. a Explain the Daisy chain interrupt priority scheme
b What are the differences between Isolated IO and Memory mapped IO.
27. Explain the different mapping methods of cache memory.
28. Explain with an example how a virtual address is translated in to Physical address.
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ANNA UNIVERSITY OF TECHNOLOGY, COIMBATORE B.E. I B.TECH. DEGREE EXAMINATIONS : APRIL I MAY 2011 REGULATIONS : 2008 SIXTH SEMESTER : EEE 080280054 - POWER ELECTRONICS TIME : 3 Hours Max.Marks : 100
PART - A
ANSWER ALL QUESTIONS
1. What are the different methods to turn on the thyristor?
2. Define latching current and Holding current
3. What is the difference between power diode and signal diode?
4. IGBT and Power MOSFET is voltage controlled device why?
5. What is the turn-off time for converter grade SCRs and inverter grade SCRs?
6. List the advantages of GTO over SCR?
7. What is meant by phase controlled rectifier?
8. Mention some of the applications of controlled rectifier.
9. Give the function of freewheeling diodes in controlled rectifier?
10. What is meant by duty-cycle?
11. Write down the expression for the average output voltage for step down and step up chopper.
12. What are the advantages of current commutated chopper?
13. Why thyristors are not preferred for inverters?
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14. List the applications of a series inverter?
15. What is meant by PWM control?
16. List the methods of reduction of harmonic content?
17. What is the difference between ON-OFF control and phase control?
18. Give note on sequence control of ac voltage regulators?
19. What is meant by step-up and step-down Cyclo-converters?
20. Write the applications of Cyclo-converter?
PART -B
(5 x 12 = 60 MARKS)
ANSWER ANY FIVE QUESTIONS
21. Derive the expressions for average output voltage and RMS output voltage of Single Phase Half Wave Controlled Rectifier with Resistive Load.
22. The full wave controlled bridge rectifier has an ac input of 160 v rms at 50 hz and a 10 ohm load resistor. The delay angle is 45 0 .Determine the average current and voltage in the load, the power absorbed by load and input power factor.
23. Explain the construction , principle of operation and Characteristics of IGBT
24. A single phase full converter is supplied from 220V, 50 Hz source. The load consists of R=12 ohm and a large inductance so as to render the load current constant for a firing angle delay of 45 degree. Determine the average output voltage, average output current, average and rms value of thyristor currents and power factor.
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25. Describe the principle of step-up chopper. Derive an expression for the average output voltage in terms of input dc voltage & duty cycle. A step-up chopper is used to deliver load voltage of 500 v from a 200v d.c source. If the blocking period of thyristor is 80 ps, compute the required pulse width.
26. Explain the operation of Single-phase half-bridge inverter with aid of relevant waveforms and derive instantaneous output voltage
27. State different methods of voltage control of single phase inverters. Describe about single PWM control with relevant waveforms.
28. Briefly explain the operation for any one type of single phase AC voltage Controller with relevant waveforms
ANNA UNIVERSITY COIMBATORE B.E. I B.TECH. DEGREE EXAMINATIONS : MAY / JUNE 2010
REGULATIONS : 2007 |
SIXTH SEMESTER - ELECTRICAL & ELECTRONICS ENGINEERING j 070280036 - POWER ELECTRONICS TIME : 3 Hours Max.Marks : 100
PART - A |
(20 x 2 = 40 MARtj.S) ANSWER ALL QUESTIONS |
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1. List the types of SCR turn on methods? I
2. Give any two important features of IGBT? j
3. What is the drawback of SCR over BJT
4. Define Safe Operating Area (SOA)?
5. Define extinction angle
6. List the control strategies available for control of ac voltage controllers.
7. Write the expression of average output voltage of the single phase full converter?
8. What is a line commutation?
9. Draw a simple step down chopper?
10. Define duty cycle of a chopper?
11. Give the relationship between input and output voltage of step up chopper?
12. List two applications of DC chopper circuits?
13. What is a line commutated inverter?
14. What is the need of return current diode in a parallel inverter?
15. Mention two advantages of current source inverters?
16. Why transistor switches are preferred in inverters than thyristor?
17. List the various types of PWM techniques
18. What is meant by multistage sequence control?
19. Bring out two advantages for HVDC system over HVAC system?
20. What are the advantages of solid state speed control?
PART - B
(5x12 = 60 MARKS)
ANSWER ANY FIVE QUESTIONS
2\y/ a) Discuss with neat sketch, series and parallel operation of thyristors? 6
b) Explain about the dv/dt and di/dt protection in an SCR 6
22... a) Draw the symbol and structure of TRIAC. Explain all the four modes of 8 operation with neat sketch, b) What is DIAC and how it differ from SCR? 4
23. A single phase semiconverter is operated from 230V, 50Hz supply. The load
current with an average value if Ia is continuous with negligible ripple
** content. The turns ratio of transformer is unity. If the delay is a = /3, calculate a) the harmonic factor of input current b) displacement factor and c) the input power factor
24, a) Explain the e.ffect of source impedance on the performance of converters. 6 b) Explain the principle of operation of a single phase to single phase 6
cycloconverte: using bridge configuration
25, a) With relevant sketches explain the operation of a voltage commutated chopper?
b) Derive an expression for the input frequency in a series inverter.
26| In a chopper circuit, the average value of the output voltage = 120 V.
If the voltage drop across the chopper switch be 1.5 volt, load resistance =
14 ohms; freq=2.3 kHz; duty cycle = 50%. Find (i) the supply voltage (ii) r.m.s. value of the voltage, (iii) chopper efficiency (iv) input resistance and
(v) r.m.s. value of the fundamental component of the output harmonic voltage.
27. a) Compare voltage source and current source inverters.
b) A single phase ac voltage controller has an input voltage of 150 V and load resistance of 8 Oiim. The firing angle of thyristors is 60.
Find (i) Average output voltage, (ii) RMS output voltage
28. Draw the block Diagram of UPS and explain briefly the function of each block?
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| Earning: Approval pending. |
