QUESTION BANk DEGREE: B.E Year/branch : III ECE SEM : V SEMESTER

VINAYAKA MISSIONS UNIVERSITY

V.M.K.V.ENGINEERING COLLEGE, SALEM

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

 QUESTION BANK

COMMUNICATION THEORY AND SYSTEMS

DEGREE: B.E

Year/branch    : III ECE

SEM        : V SEMESTER

UNIT 1

PART A

1. Define Modulation
2.  A transmitter supplies 8 KW to the antenna when unmodulated. Determine the total    power radiated when modulated to 40 %
3. List out the needs for modulation.
4. Draw the Frequency spectrum of AM wave.
5. A sinusoidal carrier signal of frequency 1 MHZ and amplitude 100V is modulated by a sinusoidal signal of frequency 5 KHZ producing 40% modulation. Calculate the frequency and amplitude of USB and LSB.
6. Differentiate between deterministic and random signals
7. Define Energy & Power signals
8. State Drichlets conditions
9. Define Modulation index and mention its range.
10. As related to AM, what is over modulation, under modulation and 100% modulation?
11. List the Limitations of AM systems.
12. Write down the expression for modulation index of multi tone modulation.
13. The total power content of an AM signal is 1kilowatt.Determine the power being transmitted at the carrier frequency and at each of the sidebands when the percentage of modulation is 100.
14. Mention the types of linear modulators.
15. Differentiate linear modulation techniques with nonlinear modulator.
16. Distinguish between synchronous and asynchronous demodulation techniques
17. What do you meant by balanced modulator?
18. What are the requirements in designing BPF in frequency discriminator for generating SSB wave?
19. List the advantages and disadvantages of SSB.
20. List the applications of VSB modulation
21. Draw the magnitude response of VSB filter wave.
22. Define frequency translation.
23. Write the applications of Frequency Division Multiplexing.
24. Define HILBERT transform
25. What do you mean by VSB modulation?

PART B

1. (i) Derive an expression for a single tone AM signal and draw its frequency spectrum.                                                                                                (8)       

         (ii) An amplitude modulated signal is represented by

V (t) = 0.1 [1 + 0.1 cos 2512 t + 0.5 cos 6280t] sin (10⁶t + 45⁰) v. What information can you gather from this?                                                                           (4)

      2. (i) Discuss the working principle of square law modulators. Mention its merits &          demerits?                                                                                                   

3. Describe the operation of Coherent detection with necessary diagram and expressions for DSBSC systems .

4. Draw the functional block diagram of Phase shift method, describe its function    to generate SSB modulation with merits and demerits.

5. With block diagram explain VSB wave generation and Mention few  application of  VSB wave.

6. Explain the principle and operation of Balanced Modulator for generation of

     DSB SC Wave with relevant expression.

7.i).With block diagram explain the concept of frequency translation, explain up      conversion and down conversion.

      ii) Compare various Amplitude Modulation systems.                                               

8.With neat block diagram explain Frequency division Multiplexing.    

9. Explain the demodulation process of AM wave with practical envelope detector.

    10. With a neat sketch explain the block diagram of AM transmitter in detail.

UNIT 2

PART A

1. Mention  the types of Angle modulation techniques
2. Define Phase modulation.
3. what is the modulation index for  Frequency modulation.
4. Illustrate the relationship between Frequency and Phase modulation with block diagram.
5. Define Frequency deviation.
6. Define the modulation index of PM.
7. Distinguish between Narrowband FM and Wideband FM.
8. State Carson’s rule for transmission bandwidth
9.  When is FM considered as AM justify your answer?
10. FM is noise free modulation technique why?
11. List the nonlinear effects in FM.
12. What are the components in frequency multiplier?
13. Distinguish between Narrowband and Wideband FM.
14. How the effects of residual AM and Harmonic PM can be reduced in a Narrow band FM.
15. Write the expression for the spectrum of a single tone FM signal
16. What is the maximum frequency deviation allowed by FM.?
17. Mention any two advantages of FM over AM.
18. Define carrier swing.
19. A 110 MHz carrier is Frequency modulated by a 93 KHz sine wave the resultant FM signal has a frequency deviation of 50 KHz determine the modulation index of the FM wave.
20. Draw the frequency spectrum of FM wave.
21. Find the Bandwidth required for a FM wave in which the modulating frequency signal is 5 KHz and the Maximum frequency deviation is 17 KHz?
22. Give the Frequency spectrum of Narrowband FM
23. Mention the major drawbacks of FM.
24. A 108.5 MHz carrier signal is frequency modulated by an 8 KHz sine wave. The resultant FM signal has frequency deviation of 50 KHz. Calculate the highest and lowest frequencies attained by the modulated signal.
25. What is the Modulation index of an FM signal having a carrier swing of 100 KHZ when the modulating signal has a frequency of 7 KHZ?

PART B

1. With neat block diagram explain the generation of Narrowband FM and give the phase comparison between FM, AM for sinusoidal modulation.
2. Derive an expression of single tone FM modulation systems and draw its frequency spectrum.
3. Describe the generation of WBFM from the basic principle using Armstrong method with neat phasor and block diagram.
4. How FM signal can be detected with the use of slope detector, explain with relevant frequency response and derive necessary parameters.
5. a) Explain in detail the Transmission Bandwidth of FM signal, with suitable diagram.                                                                                                        (8)

b) Discuss the similarity between FM and PM                                               (4)

       6.  Explain the working principle of a varactor diode method for generation of FM wave.

       7. Discuss the working of Ratio detector with neat circuit diagram.

      8. Explain the working of balanced slope detector with relevant diagram.

      9. With a neat sketch explain the Block diagram of FM Transmitter in detail.   

  10. (i)Explain the principle of operation of FM super heterodyne Receiver          (6)

         (ii) Derive the expression for PM wave.                                                            (6)

UNIT-3

       PART-A:

1. Define noise and mention the classifications of noise.
2. What is meant by thermal noise?
3. What is meant by shot noise?
4. What are the different types of man made noises which arise in the communication system.
5. Define noise figure.
6. Define noise temperature.
7. Define probability density function.
8. Give the Gaussian Probability density function.
9. Define fading.
10. What is the need of frequency domain representation of noise?
11. What is the signal to noise ratio at the output of DSB system coherent modulation?
12.  Find the thermal noise voltage developed across a resistor of 800W the bandwidth of the measurement instruments is 9Mhz and the ambient temperature is 31°C
13. What is Frii’s formula?
14. What is white noise?
15. Draw the In phase and Quadrature component of narrowband noise
16. Draw the block diagram AM receiver model
17. Mention the advantage of the noise in terms of Quadrature components.
18. List the properties of narrow band noise.
19. Define partition noise.
20. Classify the types of noise sources.
21. Define flicker noise.
22. Define equivalent noise resistance.
23. PART-B:

1. What are the different types of noise? Explain each of them.

2. What is narrowband noise? What are the two specific representation of a NB noise?

3. (i)Explain what is meant by effective noise temperature of cascaded amplifier.

(ii) Derive the relationship between noise figure and effective input temperature when two amplifiers are connected in cascade.

4. Explain in detail about shot noise and thermal noise.

     5. Obtain an expression for noise figure of CE amplifier.

6. Obtain an expression for noise figure of CB amplifier.
7. Derive the Quadrature and Inphase components of a narrowband noise

      8.  Obtain the Friis formula for effective noise figure of cascaded stages & express it in terms of noise temperature.

     

9.  Explain in detail about noise temperature & derive its expression.

     10.An amplifier has an input resistance of 1M Ohm.If the effective bandwidth of amplifier is 12 KHZ. Calculate the value of thermal noise voltage at the input terminal.     The temperature can be assumed to be 20 degree celcius.

 UNIT-4

       PART A:

1. How to achieve threshold reduction in FM receivers
2. What is FM threshold effect?
3. What is the (S/N) o / (S/N) I for AM envelope detector?
4. Draw the phasor representation of FM noise
5. What is the SNR for AM with small noise case?
6. Draw the block diagram of FM superhetrodyne receiver
7. Draw the block diagram of FMFB demodulator
8. Mention the figure of merit for FM receiver
9. Define signal to noise ratio.
10. Define figure of merit.
11. Define threshold effect.
12. What is capture effect in FM.?
13. What is the necessity of pre-emphasis and de-emphasis in FM receiver?
14. What are the advantages of super heterodyne receiver?
15. How to achieve threshold reduction in FM receiver?
16. Draw the phasor representation of FM noise.
17. What is the signal to noise ratio at the output of the DSB system in coherent detection?
18. Draw the noise spectrum of SSB-SC AM.
19. Differentiate between coherent & non-coherent detection.
20. Compare figure  of merits  for different types AM detectors.

        PART-B:

1. Obtain an expression for SNR of coherent reception of DSB-SC modulated wave.
2. Obtain an expression for SNR of AM system using envelope detector in the receiver.
3. Derive an expression for SNR in FM system.
4. Draw the block diagram of a super heterodyne receiver and explain the function of each block.
5. With the help of block diagram explain Pre-emphasis and de-emphasis.
6. Compare the noise performance of various continuous wave modulation system.
7. Derive the noise power spectral density of the FM demodulator and Explain its performance with diagram.
8. Explain the noise performance of SSB-SC AM system .
9. Explain the FM receivers model with the help of block diagram and determine the figure of merit.

     10. Define threshold effect and explain in brief.

     

 

 

 

 

 

 

 

 

UNIT 5

PART A

1. Define Information.
2. What do you mean by Entropy?
3. List the properties of Entropy.
4. State Shannon’s theorem.
5. Define coding efficiency.
6. Differentiate between Prefix code & Extended codes.
7. Mention the significance of Huffman coding.
8. What do you meant by discrete memory less channel?
9. Define Mutual information.
10. List the properties of Mutual Information
11. Define channel capacity.
12. Differentiate between source coding & channel coding.
13. State channel coding theorem.
14. Define code rate.
15. Define Information capacity.
16. Differentiate between Huffman coding & Shanon fano coding.
17. Determine the entropy for an equiprobable events
18. What is channel redundancy?
19. Name any two source coding techniques.
20. What is the capacity of the channel having infinite Bandwidths?
21. A source is emitting symbols x1, x2, & x3 with probabilities 0.5, 0.3, & 0.2 .what is the entropy of the source.
22. A source emits four symbols with probabilities P0=1/3, P1=3/8, P2=3/8 and P3=1/8. Find out the average information.
23. Write down the formula for the mutual information
24. An event has six possible outcomes with probabilities 1/2,1/4,1/8,1/16,1/32,1/32. Find the entropy of the system.

25. Explain the significance of the entropy H(X/Y) of a communication system               where X is the transmitter and Y is the receiver.

PART B     

1. Construct binary optical code for the following probability symbols using Huffman procedure and calculate code efficiency

 [0.2, 0.18, 0.12, 0.1, 0.1, 0.08, 0.06, 0.06, 0.06, 0.04]

2. Explain in detail Huffman coding algorithm and compare this coding technique with other coding techniques
3. Apply the Shannon fano coding procedure for the following message ensemble

                      [x]= { x1 x2 x3 x4 x5 x6 x7 }

                      [p]= {0.4, 0.2, 0.12, 0.1, 0.08, 0.06, and 0.04}

4. Derive the channel capacity for a continuous band limited white Gaussian noise channel.
5. Write short notes on a) Channel coding theorem b) Source coding theorem
6. A discrete memory less source has an output of seven symbols with probabilities for its output as given below:

Symbol	x1	x2	x3	x4	x5	x6	x7
Probability	0.4	0.2	0.12	0.08	0.08	0.08	0.04

Compute the Huffman code. Let the encoding alphabet be -101, M = 3. Find its efficiency.

  7.    Encode the following source using Huffman procedure and find the coding        efficiency.

Symbol	S0	S1	S2	S 3	S 4	S 5	S 6
Probability	0.25	0.25	0.125	0.125	0.125	0.0625	0.0625

                                              

8. Apply Shannon fano coding for the following message ensemble

X=	x 1	x 2	x 3	x 4	x 5	x 6	x 7
P=	0.4	0.2	0.12	0.08	0.08	0.08	0.04

Calculate its efficiency.

9. Write short notes on:i).Discrete memory less channel.                                       ( marks)

ii).Noise free channel.                                                               (5 marks)

10. Prove that

       i).H(X, Y) =H(X/Y) +H(Y) 

                                                 

                                          SUBJECT: LIC & IT’S APPLICATIONS

CLASS/SEM/DEPT: III YEAR / V SEM / ECE

UNIT I

PART A

1. Define an operational amplifier.
2. Mention the characteristics of an ideal op-amp.
3. What happens when the common terminal of V⁺ and V^- sources is not grounded?
4. Define input offset voltage.
5. Define input offset current. State the reasons for the offset currents at the input of the op-amp.
6. Define CMRR of an op-amp.
7. What are the applications of current sources?
8. Justify the reasons for using current sources in integrated circuits.
9. What is the advantage of widlar current source over constant current source?
10. Define slew rate.  What does it signify
11. Draw a neat sketch showing the frequency response of op-amp 741 .
12. What is frequency compensation.
13. What is differential amplifier and list the types.
14. Define Linear IC.  State its advantages.
15. Differentiate linear IC from Digital ICs.
16. Define Current Source.
17. Draw the internal Block of an Op-Amp.
18. What are the Different Linear IC packages?
19. Why is R_E is replaced by a constant current bias circuit in a Difference Amplifier?
20. What is the advantage of using Active load in Difference Amplifier?
21. Compare Constant Current bias and Current mirror Methods.
22. What are the Techniques available to compensate the Variation in CMRR?
23.  What are the advantages of Band gap Reference Circuit?
24. List the types of Frequency Techniques Available.
25. What are the causes of Slew Rate?

PART B

1.      Explain the working of a Current Source with a circuit diagram.

2.      Explain the operation of a basic differential amplifier.

3.      Draw the circuit diagram of a symmetrical emitter coupled difference amplifier and show that a very high CMRR   will result if the difference amplifier is supplied by a constant current bias.

4.      Draw and explain the circuit diagram of a basic current mirror and improved current mirror circuit.

5.      a)What are the ideal characteristics of Op-amp

b) Explain band gap reference circuit

6.      Explain the frequency compensation Techniques used in operational amplifiers.

7.      Explain the differential amplifier circuit with active load to improve Common mode gain.

8.      Explain in detail Widlar Current Source.

9.      Explain supply independent biasing using zener referenced bias circuit.

10.  Draw and explain in detail about Slew rate and methods of improving slew rate.

UNIT II

PART A

1.      Mention two characteristics of Instrumentation Amplifier.

2.      Mention two applications of Schmitt Trigger.

3.      State the disadvantages of passive filters.

4.      Draw an integrator circuit using op-amp .

5.      Write the advantages of active filter over passive filter.

6.      Draw the circuit diagram of full wave precision rectifier.

7.      What are the areas of application of non-linear op-amps circuits?

8.      What are the limitations of the basic differentiator circuit?

9.      Derive the gain of an op-amp Buffer.

10.  What are AF and RF op-amp Oscillators?  Give examples.

11.  What is an Op-amp Buffer?  State its advantages.

12.  Draw the differentiator circuit using Op-Amp.

13.  Draw and mention the equation for Non-inverting summing amplifier.

14.  Draw and mention the equation for Adder- Subtractor circuit using Op-Amp.

15.  Mention some of the linear applications of op – amps

16.  Mention some of the non – linear applications of op-amps

17.  What are the applications of V-I converter?

18.  What do you mean by a precision diode?

19.  Write down the applications of precision diode.

20.  List the applications of Log amplifiers

21.  Draw the Inverting and Non Inverting Amplifier Circuits.

22.  What is Multivibrator and list its types.

23.  Draw the Circuit of a full wave rectifier.

24.  Write the expression for Log and Anti Log Amplifier.

25.  Differentiate between astable and monostable Multivibrator.

PART B

1. Explain the working principle of RC phase shift oscillator with neat sketch.
2.  Explain the  working of:

                                                              i.      Schmitt trigger

                                                            ii.      Comparator

3. Derive the Closed Loop voltage gain equation for Inverting and Non Inverting Amplifier.
4. Explain the working of

(i)                  Voltage to Current Converter

(ii)               Triangular  Wave Generator

5.  Explain Instrumentation Amplifier with a neat diagram and derive its gain.
6. Discuss in detail the operation of Astable Multivibrator.
7. Discuss in detail the operation of Monostable Multivibrator.
8. Explain the following op amp applications with a  neat circuit diagram and derivations:

(i)                  Integrator

(ii)               Differentiator

9. Draw a neat Op-Amp Low pass Butterworth filter and derive the design equations.
10. A) Derive an expression for the output voltage of op-amp anti-log amplifier.

B) Derive an expression for the output voltage of op-amp log amplifier.

UNIT III

PART A

1. What is amplitude modulation.
2. Define lock range
3. What is a two quadrant multiplier.
4. With reference to a VCO, define voltage to frequency conversion factor K_v.
5. What is a four quadrant multiplier.
6. Define capture range of a PLL.
7. Name two applications of PLL.
8. What is a voltage controlled oscillator.
9. Define Compander and its purpose.
10. Mention some areas where PLL is widely used.
11. Define Lock-in range of a PLL.
12. Compare the features of digital multiplier with analog multiplier.
13. List down the important electrical characteristics of 565 PLL.
14. Draw a neat block diagram of VCO.
15. What are the advantages of Compander IC.
16. List the basic building blocks of PLL
17. What are the three stages through which PLL operates?
18. Give the classification of phase detector

19.  What is a switch type phase detector?

20.  What are the problems associated with switch type phase detector?

21.  What is a voltage controlled oscillator?

22.  Discuss the effect of having large capture range.

23. List the Applications of VCO.
24. Mention the Advantages of Frequency Synthesizers in Integrator Circuits.
25. Draw FSK De-Modulator circuit using IC565.

PART B

1. Briefly explain the block diagram of PLL and derive the expression for Lock range and capture range.
2. With a neat functional diagram, explain the operation of VCO. Also derive an expression for f₀.
3. Analyze the Gilbert’s four quadrant multiplier cell with a neat circuit diagram. Discuss its applications.
4. Briefly discuss the applications of PLL
5. Explain in detail about AM demodulator        
6. Explain in detail about PM demodulator         
7. Explain in detail about FSK demodulator
8. Explain frequency synthesizers with a neat Diagram.
9. Compare PM, AM and FSK demodulators.

UNIT IV

PART A

1. What is Sample and Hold Circuit?
2. What is Digital to Analog converter and Classify it.
3. How many comparators are required to build an n bit flash type A/D converter.
4. Why is the R-2R ladder network DAC better than weighted resistor DAC.
5. Which type of ADC is used in all digital voltmeters.
6. Define monotonicity with respect to D/A converter.
7. List the Applications of Sample and Hold Circuits.
8. Define Settling time of DAC.
9. What is granular noise.
10. List advantages of ADM.
11. Explain in brief the principle of operation of successive approximation ADC.
12. Mention the Advantages of sample and hold circuit.
13. Which is the simplest DAC? Why?
14. Why MOSFET is used in Op-amp Sample and Hold circuit.
15. What are the parameters of ADC and DAC?  List them.
16. What is Delta Modulation?
17. Classify Different types of Voltage to frequency converters.
18. Compare Single slope and Dual slope converters.
19. List out some integrating type converters.
20. What is integrating type converter?
21. Define conversion time.
22. Define accuracy of converter.
23. Give some specification for Voltage to frequency converter.
24. Define Offset Error and Linearity Error.
25. Define Quantization Error.

PART-B

1.      What is integrating type converter? Explain the operation of dual slope ADC

2.      Explain the principle of operation of successive Approximation ADC.

3.      With neat sketch explain the operation of sample and hold circuit.

4.      Explain the various types of digital to analog converters.

5.      What is delta sigma modulation? Explain the A/D conversion using Delta modulator      

6.      Explain delta modulation with neat diagram.

7.      Explain flash type ADC with diagram.

8.      Draw and explain voltage to time and Voltage to frequency converters.

9.      Explain in detail about various analog switches.

10.  Explain Binary weighted resistor DAC

UNIT V

PART A

1. Name a timer IC and a voltage regulator IC.
2. Define ripple rejection with respect to voltage regulators.
3. Why is that a switching regulator has a higher efficiency than a series regulator.
4. What is the roll off rate for a third order low pass filter.
5. Name the two packages in which IC 555 timer is available.
6. Why do switching regulators have better efficiency than the series regulators.
7. Define line regulation.
8. What is noise.
9. What is shot noise.
10. List the main features of timer IC 555.
11. Draw the PIN Diagram of IC 555 Timer.
12. What is an Isolation amplifier.
13. Define voltage regulation.  Calculate its percentage for an ideal voltage regulator.
14. What are the types of noises that are introduced in op amp.
15. What is Linear mode power supply?
16. What is an optocoupler?  State its advantages.
17. List the application of Astable multivibrator using IC 555.
18. Define duty Cycle.

19.  What is tuned amplifier?

20. Mention the characteristics of voltage Regulator.
21. Classify the types of voltage regulator.
22. List the advantages of Switched capacitor.
23. What is an power amplifier and classify its types.
24. Draw the waveform of Class C Amplifier.
25. Draw the block diagram of fiber optic network.

PART-B

1.      What is 555 timer? What are the features of 555 timer? Explain the monostable mode in detail?

2.      Explain the Astable mode of operation using 555 timer.

3.      Explain in detail about Class A and Class B Power Amplifiers.

4.      Explain in detail the 723 IC general purpose voltage regulator.

5.      Draw and explain the operation of switching regulators. Give its advantages.

6.      Explain the functional diagram of LM 380 power amplifier.

7.      Explain tuned amplifier with neat diagram.

8.      Briefly discuss in detail about video amplifier with neat sketch.

9.      Explain opto-coupler in detail.

10.  With neat diagram explain isolation amplifier.

                                                      (6 marks)

       ii).H(X, Y) = H(Y/X) +H(X)                                                    (6 marks)

                                           

TRANSMISSION LINES AND WAVEGUIDES

UNIT I

PART A

1. Define Characteristic impedance.
2. Define Propagation constant.
3. What is a finite line? Write down the significance of this line?
4. What are the types of line distortions?
5. How to avoid the frequency distortion that occurs in the line?
6. What is a distortion less line? What is the condition for a distortion less line?
7. What is the drawback of using ordinary telephone cables?
8. What is loading?
9. What is patch loading?
10. Define reflection coefficient.
11. When reflection occurs in a line?
12. What are the conditions for a perfect line? What is a smooth line?
13. List the parameters of a transmission line?
14. State the conditions for a distortion less line.
15. Define phase velocity and group velocity.
16. What are the disadvantages of parallel open wire line?
17. What do you mean by loading of transmission line?
18. What is the principle of reflection phenomenon?
19. Why is waveform distorted in transmission line?
20. A transmission line with a characteristic resistance of 50 ohm is connected to a 100-ohm resistance load. Calculate the voltage reflection coefficient at the load.
21. Mention the characteristics of an infinite line.
22. Write a note on i) Reflection loss ii) Insertion loss.
23. What are the practical considerations of underground cable?
24. Write a note on Telephone cable.
25. What is return loss?

PART B

1.      i) Develop the differential equations governing the voltage and current at any point on a        uniform transmission line, and then solve these to obtain the voltage and current in terms of the load current and voltage.

ii) Explain physical significance of a general solution of transmission line.

2.      i) Derive the equations of attenuation constant and phase constant of a transmission line in terms of the line constants R, L, C and G.

ii) A generator of 1 V, 1 KHz supplies power to a 100 km open wire line terminated         in 200 Ω resistance. The line parameters are R = 10 Ω/ Km, L = 3.8 mH / Km, G = 1 x 10 ^-6 mho/ Km, C = 0.0085 uF/ Km.

Calculate the input impedance, reflection coefficient and sending end current.

3.      i) Show that a line will be distortion less if CR = LG.

ii) A transmission line has the following per unit length parameters

R = 52 Ohm/m, L = 0.1 uH / m, C = 300 pF / m, G = 0.01 mho/m

Calculate the propagation constant and characteristics impedance of transmission line at 500 MHz; obtain the same parameters for loss less line.

4.      i) Derive the expression for input impedance and transfer impedance interms of Z_O,   Z_R and propagation constant p.

ii) Derive the expression for α and β for continuous loading also list out its advantages and disadvantages.

5.      i) Derive the expression for the insertion loss of transmission line.

ii) A transmission line has Z_{O =}700∟-13.4^o ohm is inserted between a generator of 200 ohm and a load of 400 ohm. The attenuation and phase constant of                         the line is α = 0.00712 neper / Km and β = 0.0288 rad / Km. Calculate the insertion loss if the length is 200 Km.

6.      What is lumped loading? Derive Campbell’s equation for lumped loading.

7.      Describe the expression of a line not terminated in Z_0.

8.      Derive the expression for insertion loss on a line.

9.      A transmission line of 2 miles long operates at 10 kHz and has parameters R=30 Ω/mile, L=2.2mH/mile, C=80nF/mile and G=20nV/mile. Find the characteristic impedance, propagation constant, attenuation and phase shift per mile.

10.  Find the sending end impedance of the line having Z_o=710∟14^o, υ=0.007+j0.028/km,Z_R=300 ohm, l=100 km.

UNIT II

PART A

1. State the assumptions for the analysis of the performance of the radio frequency line.
2. State the expressions for the capacitance of   an open wire line.
3. What are nodes and antinodes on a line?
4. What is the range of values of standing wave ratio?
5. What is called standing wave ratio?
6. How will you make standing wave measurements on coaxial lines?
7. Give the input impedance of dissipationless line.
8. What is the application of the quarter wave matching section?
9. Explain impedance matching using stub.
10. Give the formula to calculate the length of the short circuited stub.
11. List the applications of the smith chart.
12. What are the difficulties in single stub matching?
13. Give reason for an open line not frequently employed for impedance matching.
14. Why Double stub matching is preferred over single stub matching.
15. What are small dissipation line and zero dissipation line?
16. Draw the sketches showing variations of input impedance of a short circuited dissipation less line as a function of wave length.
17. Define standing wave ratio.
18. Write the expression for input impedance of RF line.
19. What is the condition for a line to have zero dissipation?
20. A 50 ohm line is terminated in load Z_R (90+j60). Determine VSWR due to this load.
21. Draw a net sketch of variation of input impedance of an open circuited dissipation less line.
22. Write down the expression for the voltage at a point S away from the receiving end interms of reflection coefficient.
23. List out the approximations be employed for simplified analysis of line performance at radio frequencies.
24. Distinguish between nodes and antinodes.
25. A line with characteristic impedance of 692∟-12º is terminated  with 200 ohm resister. Determine K.

PART B

1. Discuss how a smith chart is constructed and explain its applications.
2. Explain the following:

      i) Single stub matching.          ii) Double stub matching.

3. Derive the expression of circle diagram for the transmission line.
4. A dipole antenna whose input impedance is 100 ohm is to be matched at frequency of 100 MHz to a transmission lines having Z_o of 600 ohm   by means of short circuit stub. Determine the location and length of the stub.
5. Determine the SWR, characteristic impedance of the quarter wave transformer, and the distance the transformer must be placed from the load to match a75 ohm , transmission line to load Z_L=25-j50 ohm.
6. Determine the input impedance of open and short circuited dissipationless transmission line.
7. Explain about one eighth wave line and quarter wave line.
8. Define and explain the following

i)        Standing waves

ii)      Standing wave ratio

iii)    Relation between SWR and ‘K’.

iv)    A method to measure SWR.

9. Discuss the measurement of power and impedance on transmission line using phasor diagrams.
10. Explain the method of measurement of standing wave ratio  in open wire line.

UNIT III

PART A

1. What are guided waves? Give examples.
2. What is cut off frequency?
3. Mention the characteristics of TEM waves.
4. Define attenuation factor.
5. Give the relation between the attenuation factor for TE waves and TM waves
6. Why are rectangular wave-guides preferred over circular wave-guides?
7. Mention the applications of wave guides.
8. What is a TEM wave or principal wave?
9. What is TH wave or E wave?
10. Distinguish TE wave and TM wave?
11. What is a principal wave?
12. Give the dominant mode for TE and TM waves
13. Mention the characteristics of TEM waves.
14. What are micro strip lines?
15. What are the losses associated with microstrip line?
16. What are the disadvantages of micro strip lines?
17. What is a parallel plate wave guide?
18. What is a wave-guide?
19. Write the properties of TEM waves.
20. Write the point form of Maxwell’s equation.
21. Write the condition of good conductor.
22. Write the integral form of Maxwell’s equation.
23. A pair of perfectly conducting planes is separated 4 cm in air. For a frequency of 5000 MHz with TM₁ mode, find cut off wavelength.
24. Write the differential form of Maxwell’s equation.
25. For a frequency of 6000 MHz and plane separation of 7 cm, find critical wavelength.

PART B

1. Derive the electromagnetic field expressions for waves guided by a parallel conducting plane?
2. (i) Bring out the differences between  TE,TM and TEM waves.

(ii) Find the cut-off frequency for the TE₁ mode for the frequency of 6000 MHz and plane separated by 7 cm.

3. Derive an expression for attenuation factor for TEM waves in two parallel conducting planes.
4. Define wave impedance. Obtain the expression for wave impedance of TE, TM and TEM waves in two parallel conducting planes.
5. Explain about the velocity propagation of guided waves..
6. Derive the expressions for the field components of TM waves in a parallel plane waveguide.
7. For the frequency of 6000 MHz and plane separation of 7 cm, find the following for TE₁ mode.

i)        Critical frequency

ii)      Phase constant

iii)    Attenuation constant

iv)    Critical wavelength.

8. Write the properties of TEM waves. Write different characteristics of TE and TM waves.
9. Discuss the characteristics of TE and TM waves and also derive the cutoff frequency and phase velocity from the propagation constant.
10. A parallel plane waveguide with plate separation of 20 cm with TE₁ mode excited at 1 GHz. Find the phase constant.

UNIT IV

PART A

1. Why is rectangular form used as waveguide?
2. What is the dominant mode for the TE waves in the rectangular waveguide?
3. What is the dominant mode for the TM waves in the rectangular waveguide?
4. Which  are  the  non-zero  field  components  for  the  TM11   mode  in  a rectangular waveguide?
5. Define characteristic impedance in a waveguide.
6. Explain why TM01 and TM10 modes do not exist in a rectangular waveguide?.
7. What are degenerate modes in a rectangular waveguide?
8. What is the dominant mode for the rectangular waveguide?
9. What is a wave-guide?
10. Mention the applications of wave guides.
11. Why is circular or rectangular form used as waveguide?
12. What is the dominant mode for the rectangular waveguide?
13. Which are the non-zero field components for the TE₁₀ mode in a rectangular waveguide?
14. Which are the non-zero field components for the TM₁₁ mode in a rectangular waveguide?
15. Define characteristic impedance of rectangular waveguide.
16. Why TEM mode is not possible in a rectangular waveguide?
17. Why TM₀₁ and TM₁₀ modes in a rectangular waveguide do not exist?
18. Write the boundary conditions in rectangular wave guide.
19. Define cutoff wavelength.
20. Draw the field pattern for TE₁₁ mode.
21. Find λ_c for a standing rectangular wavelength for TE₁₁ mode
22. Define the phase velocity and group velocity.
23. A rectangular wave guide has the following dimensions l = 2.54 cm, b = 1.27 cm wavelength thickness = 0.127 cm. Calculate the cutoff frequency for TE₁₁ mode.
24. What are degenerate modes in rectangular waveguide?

PART B

1. Derive the expressions for the field components of TM waves in a rectangular waveguide.
2. Derive the expressions for the field components of TE waves in a rectangular waveguide.
3. Derive an expression for attenuation factor in a rectangular waveguide for TE and TM waves.
4. Explain how various modes can be excited in a rectangular waveguide.
5. Derive an expression for wave impedance for TE and TM waves in rectangular waveguide.
6. Explain the characteristic impedance of a rectangular waveguide and derive the expression for TE, TM and TEM waves.
7. When the dominant mode is propagated through a wave guide at a frequency of 9 GHz the wavelength is found to be 4 cm. Find the dimension of breadth  of the guide.
8. The cutoff wavelengths of a rectangular waveguide are measured to be 8 cm and 4.8 cm for TE₁₀ and TE₁₁ modes respectively. Determine Waveguide dimensions.
9. Briefly explain the transmission line and wave guide.
10. Discuss the attenuation of Electromagnetic wave guide along rectangular waveguide.

UNIT V

PART A

1. What is a circular waveguide?
2. Why circular waveguides are not preferred over rectangular waveguides?
3. Mention the applications of circular waveguide.
4. What are the possible modes for TM waves in a circular waveguide?
5. Mention the dominant modes in rectangular and circular waveguides.
6. What are the possible modes for TE waves in a circular waveguide?
7. What is the dominant mode in a circular waveguide?
8. What are the performance parameters of microwave resonator?
9. Define quality factor of a resonator.
10. When a medium is said to be free- space?
11. What is the dominant mode for TE waves in a circular waveguide?
12. What are the root values for the TM modes?
13. Write down the expression for the wave impedance of TM waves in circular wave guide.
14. Define Q of a wave guide.
15. Write the attenuation factor for TE₁₀ mode in circular wave guide.
16. Why is TM₀₁ mode preferred to the TE₀₁ mode in a circular waveguide?
17. Write the note on excitation of waveguides.
18. Draw the field patterns for the dominant mode of TE_mm wave in the circular waveguide.
19. How the TE₁₀ mode is launched in rectangular waveguide using a probe?
20. Which is the most dominant mode in rectangular waveguide? Why?
21. What is the Bessel’s function?
22. Write the note on guide terminations.

PART B

1.      Derive the expressions for the field components of TM waves in a circular waveguide.

2.      Derive the expressions for the field components of TE waves in a circular waveguide.

3.      Derive an expression for attenuation factor in a circular waveguide for TE and TM waves.

4.      Explain the various methods of excitation modes in circular wave guide.

5.      Discuss about the wave impedance in circular wave guide.

6.      Given the circular waveguide of internal diameter 12 cm operating with a 8 GHz. Signal propagating TM₂₂ mode. λ₀, λc, and λg.

7.      Determine the solution of electric and magnetic fields of TM waves guided along circular waveguide.

8.      Derive TM wave components in circular waveguides using Bessel function.

9.      Derive the cutoff frequency, phase shift constant and velocity of propagation of waves in a circular waveguide.

10.  A cylindrical copper tube of diameter 3 cm is air filled. Calculate cutoff frequencies in TE₀₁, TM_01, TE₁₁ and TM₁₁ modes. 

                           

ELECTRONICS CIRCUITS II

QUESTION BANK

UNIT I - FEEDBACK AMPLIFIERS

2 MARK QUESTIONS:

1. Define Negative and Positive Feedback.

2. Define Feedback factor.

3. Explain Desensitivity

4. Explain Sampling Network

5. What are the advantages of Negative Feedback over Positive Feedback?

6. Draw the frequency response of amplifier with feedback and without feedback.

7. What are the effects of negative feedback on distortion and gain?

8. Explain the term Sensitivity.

9. Distinguish between Voltage and Current feedback.

10. Distinguish between shunt and series feedback.

11. List the four types of negative feedback?

12. Draw the equivalent circuit of a Transconductance amplifier?

13. Draw the equivalent circuit of a voltage amplifier?

14. Find closed loop gain of a negative feedback amplifier with open loop gain 600, β=0.01?

15. What are the effects of negative feedback on input and output impedance of amplifier?

16. Explain the effect of noise and distortion in feedback amplifier?

17. Write the formula for closed loop gain?

18. What is the basic difference between feedback in biasing circuits and amplifier circuits?

19. What is open loop gain?

20. Why negative feedback is employed in high gain amplifiers?

21. Define (i) Gain Margin and (ii) Phase Margin.

22. Distinguish positive and negative feedback amplifier.

23. What type of feedback has been used in an emitter follower circuit?

24. An amplifier with stage gain 200 is provided with negative feedback of feedback ratio 0.05.

       Find the new gain.

12.MARK QUESTIONS:

1.Explain with relevant information how the negative feedback amplifier improves     

   stability, reduces noise and increases input impedance.

2.a).Draw the block diagram of amplifier with negative feedback and explain.

   b).Explain the consequences of introducing negative feedback in small signal amplifiers .

3.What type of feedback is employed in emitter follower amplifier derive an expression for    

   A_if, A_vf, R_if, R_of

4.What is the effect of negative feedback on input and output resistance of current shunt

  feedback amplifier.

5.What type of feedback is employed in a common emitter circuit with unbypassed emitter

   resistance explain.

6. Explain the effect of negative feedback on current shunt feedback amplifier derive an

   expression for A_if, A_vf, R_if, R_of.

7.For the circuit shown in the figure.

            (a).Identity the topology of feedback with proper reasoning.

            (b).Find A_if, A_vf, R_if, R_of, A_i 

8. For the feedback amplifier shown in the figure.

    Identity the topology of feedback with proper justification. The transistors used are

    identical with the following parameters.

    h_fe = 200, h_ie = 2K, h_re = 10 ^{- 4}, h_oe = 10 ^{- 6} A/V

    Calculate i) A_vf   ii) R_if   iii) R_of

           

9.In the FET amplifier shown in fig. has the following parameters rd = 40 K g_m = 2.5A/V.

   Assume all capacitors to be arbitrarily large. Calculate D,R_Mf, A_vf, R_if,R_of and R’_of .

10.The two stage feedback shown in fig. uses FET.The parameters are rd = 10 K and μ = 40.

      i) Identify the topology of feedback.

     ii) Calculate  D, A_vf, R_if,R_of and R’_of .

UNIT II - OSCILLATORS

2 MARK QUESTIONS

1. What is Oscillator circuit?

2. What are the classifications of Oscillators?

3. Define Barhausen Criterion.

4. What are the types of feedback oscillators?

5. State the conditions for oscillation?

6. Define Piezoelectric effect.

7. Draw the equivalent circuit of crystal oscillator.

8. What is Miller crystal oscillator? Explain its operation.

9. State the frequency for RC phase shift oscillator.

10. Define Oscillator

11. Differentiate amplifier and oscillator.

12. What are the advantages of crystal oscillator?

13. Draw the circuit diagram of a twin –T RC oscillator?

14. What is the advantage of a Clapp oscillator over Colpitt’s oscillator?

15. What type of feedback is used in oscillators, why?

16. Why a crystal oscillator has a higher degree of frequency stability?

17. What is negative resistance oscillator? Give an example.

18. Distinguish between LC and RC oscillators?

19. Name two low frequency oscillators?

20. Name two high frequency oscillators?

21. What is a damped oscillation?

22. What is sustained oscillation?

23. Why it is difficult to have a variable frequency operation in a RC phase shift oscillator?

24. Give expression for frequency of oscillation for colpitts and Hartley oscillator?

25. In an Hartley oscillator, if L₁ = 0.2 mH, L₂ = 0.3 mH and C = 0.003 µF, calculate the frequency of its oscillation.

12 MARK QUESTIONS:

1. With simple diagrams explain the operation of negative resistance oscillator using  tunnel diode?.

2. Draw the circuit diagram of  RC phase shift oscillator and explain its operation.

3. Explain Clapp’s oscillator and derive the expression for frequency of oscillation . Also explain

    how frequency stability can be improved Clapp’s oscillator.?

   4. Explain Hartley oscillator and derive the equation for oscillation ?

5. Explain the resonance frequency of crystal. And draw the pierce crystal oscillator circuit and derive the equation for oscillation?

6.a).Explain with suitable example how logic gates are used as linear amplifier.

   b).Explain in brief the Barhausen Criterion for oscillation in feedback oscillator.

7.a).What are  the advantages and disadvantages of wein bridge oscillator.

   b).Brief about frequency ranges of RC and LC oscillators.

8.Draw the circuit diagram of transistorized of colpitts oscillator. State the expression for the

   frequency of operation of colpitts oscillator. 

9. With a neat diagram explain Wein-bridge oscillator, and derive the expression for  frequency of oscillation.

10. Derive the frequency of oscillation for Twin-T oscillator, and explain its operation with neat circuit diagram.

UNIT III - TUNED AMPLIFIERS

2 MARK QUESTIONS:

1. What do you mean by Tuned Amplifiers?

2. What is a synchronously Tuned amplifier?

3. Mention the need of Stagger Tuned amplifier.

4. What is meant by Unloded and Loded Q of tank circuit.

5. Write a short notes on Coil losses.

6. Define Q.

7. List the advantages and disadvantages of tuned amplifier.

8. What is Neutralization?

9. List the various types of tuned amplifier.

10. What is the effect of Cascading single tuned amplifier on bandwidth.

11. Draw the circuit diagram of class C tuned amplifier?

12.  Draw the circuit diagram of a stagger tuned amplifier?

13.  What is meant by differential amplifier?

14.  Draw the circuit of an emitter coupled differential amplifier?

15.  How we improve CMRR in differential amplifier?

16.  Mention the bandwidth of a double tuned amplifier?

17.  Point out the different methods of coupling the load to a tuned amplifier?

18.  Compare the advantages of double tuned amplifier over single tuned amplifier?

19.  What is meant by loaded and unloaded Q of tank circuit?

20.  Mention the applications of Class C tuned amplifier?

21.  Write short notes on coil losses in tuned amplifier?

22.  What do you understand by instability of tuned amplifiers?

23.  Mention some stabilization techniques in tuned amplifiers?

24.  Write about the efficiency of Class C tuned amplifier?

25.  What is meant by narrowband neutralization?

12 MARK QUESTIONS:

1.With a circuit diagram explain the performance of single tuned inductively coupled amplifier.

2.a).Explain Hazeltine method of neutralization.

   b).Brief the principle of Stagger tuning.

3.Explain with circuit diagram the operation of double tuned amplifier.

4.Compare and explain the frequency response of single tuned , double tuned & stagger tuned

   amplifier.

5.Draw the circuit diagram of a Class-C transistor mixer circuit and describe its operation.

   List few application of the circuit .

6.a). Explain the concept of stagger tuned amplifier with the help of frequency response

   b).Explain Hazeltine neutralization circuit with the help of neat diagram.

7.Derive an expression for tunning frequency of a single tuned amplifier in terms of quality

   factor and bandwidth of amplifier.

8.What is the effect of cascading a single tuned and double tuned amplifiers on   

   bandwidth?. Derive the expression for it.

9.Explain the various Neutralization techniques.

10.a).Discuss instability of tuned amplifier.

     b).Explain the basic mixer circuit with neat diagram.

UNIT IV - MULTIVIBRATOR CIRCUITS

2 MARK QUESTIONS

1. What do you understand by Symmetrical triggering?

2. Why Commutating capacitors are used in bistable Multivibrator?

3. Draw the typical waveform at base and collector of a collector coupled astable multivibrator.

4. What are the applications of Schmitt trigger circuit?

5. What is Bistable multivibrator?

6. State the application of astable multivibrator.

7. What is hysteresis?

8. Explain unsymmetrical triggering.

9. Give the difference between ideal and practical emitter coupled astable multivibrator.

10. What is resolving time?

11. What is the function of commutating capacitance in multivibrator?

12. Draw the circuit diagram of a collector coupled astable multivibrator using complementary transistors?

13. Sketch the output wave form of a Schmitt trigger circuit for sine wave input of 12 V peak topeak if UTP=5V and LTP=3V?

14. What is a Schmitt trigger circuit?

15. What are the applications of bistable multivibrator?

16. Why an astablemultivibrator is called as free running oscillator?

17. What is the difference between astable multivibrator and monostable multivibrator?

18. Draw the typical waveforms at base and collector of a collector coupled astable multivibrator?

19. Define resolving time of bistable multivibrators?

20. Define storage time of multivibrator?

21. Define symmetrical triggering?

22. What is meant by linear wave shaping circuits?

23. Define transition time of bistable multivibrator?

24. What are the applications of Schmitt trigger circuit?

25. What are the triggering methods of multivibrators?

26. What do you know about speed up capacitors?

27. How will you calculate switching times of mutivibrators?

12 MARK QUESTIONS:

1.Describe the circuit diagram of emitter coupled Monostable Multivibrator and explain its

   operation with relevant waveform.

2.Explain the unsymmetrical and symmetrical triggering of bistable multivibrator .

3.a).Draw the circuit diagram of complementary transistor monostable multivibrator and explain

        its operation.

   b).Explain UTP & LTP of Schmitt triggering.

4.Describe the performance of collector coupled astable multivibrator with relevant diagram.

5.With a neat diagram explain the operation of Schmitt trigger circuit.

6.Derive the expression for the frequency of the emitter coupled astable multivibrator circuit .

7.a).Draw the transfer characteristics of Schmitt trigger and explain what is hysteresis.

   b). Write a note on complementary multivibrator circuit.

8.The circuit parameter of a fixed bias bistable multivibrator are V_cc=V_bb=5V, R_c=1k, R₁=5K,

   R₂=2.5K.The npn silicon transistor used have (h_fe)_min=20.Assume all junction voltages to be  

   zero

    a).Calculate stable state currents and voltages. verify that one transistor is in saturation and

        other in cutoff.

    b).find the maximum Icbo at which the circuit satisfactorily.

9.a).What is the effect of loading in fixed bias binary? Explain the procedure of calculating

       heaviest load which binary can derive.

   b).Write a note on free running multivibrator.

10.Design a collector coupled monostable multivibrator for following specification:

    

     I_CBO and voltage  across saturated transistor are negligible.

     For transistor ( h_fe )_min = 20 and base-emitter cut off voltage for transistor normally to be

     OFF is –1V.The base drive  to transistor in saturation is 50% in excess of minimum required.

     The collector supply ic V_cc = 6V and collector current is 2mA.The delay time is  3000μsec. 

     Chose  R₁=R₂.find R_c,R,V_BB,R₁ and C

UNIT V - BLOCKING OSCILLATOR TIME BASE GENERATOR

2 MARK QUESTIONS

1. Mention the application of blocking oscillator.

2. How the linearity of current sweep generator can be improved.?

3. Draw the circuit diagram of astable blocking oscillator.

4. Mention the features of Millers saw tooth generator.

5. What is the effect of saturation voltage on pulse width?

6. Define duty cycle.

7. Explain the use of high pass RC circuit as a differentiator.

8. Give the features of Millers sweep circuit.

9. Which portion of UJT characteristics is used in UJT saw tooth generator.

10. How linearization is achieved in current time based circuit.

11) Draw the circuit diagram of a free running blocking oscillator?

12) What is a blocking oscillator?

13) What are two types of blocking oscillators?

14) Mention few methods of controlling the pulse?

15) Draw the equivalent circuit of pulse transformer?

16) How is the total pulse of pulse transformer divided?

17) What are the characteristics of diode controlled circuit?

18) What are applications of pulse transformers?

19) Draw the circuit diagram of simple current time base generator?

20) Draw the circuit diagram of an astable blocking oscillator (RC controlled)?

21) Draw the monostable blocking oscillator using emitter based timing?

22) What is frequency control using core saturation?

23) Write short notes on push pull operation of astable blocking oscillator?

24) What are UJT saw tooth generators?

25) What is meant by linearization using constant current circuit?

26)  Where is bootstrap generators used?

12 MARK QUESTIONS:

1.Explain with suitable diagram the performance of Monostable blocking oscillator.

2.a).Explain how saw tooth waveform are generated using UJT.

   b).Discuss about linearization using constant current source.

3.With a neat diagram explain the operation of Bootstrap circuit .

4.Draw the circuit diagram of monostable transistor blocking oscillator with emitter timing.

   Explain its operation with equivalent circuit during pulse formation .

5.Explain the basic principles of miller sawtooth generator circuit with the help of neat diagram.

6.Derive the expression for slop error and sawtooth generator speed for bootstrap sawtooth

   generator circuit.

7.Draw and explain the operation of diode controlled astable blocking oscillator .

8.What is the condition on RL required for the successful operation emitter timing block

   oscillator.

9.Explain how darlington pair reduces the slop error in bootstrap saw tooth generator circuit.

10.Explain the following methods of controlklinng the pulse width in monostable blocking

     oscillator

    a).core saturation method

    b).shorted delay line method.        

               

                                      Subject Name        : COMPUTER ARCHITECTURE

                                                          Year / SEM: III Year / V Sem ECE

Unit I

Part – A

1)      What is computer program?

2)      Draw the basic functional units of a computer.

3)      What is meant by Program Counter?

4)      Define assembly language.

5)      What is an assembler?

6)      Illustrated a structure of Typical Memory hierarchy.

7)      What is Byte addressability?

8)      What are different types of data used in an instruction?

9)      Write the definition of the term “computer architecture”?

10)  List the elements of computer.

11)  Define IR.

12)  Convert decimal number into binary number

i.                    19

ii.                  12

13)  Define stack pointer.

14)  Draw the single bus structure of the processor.

15)  What is pipelining?

16)  Difference between RAM & ROM.

17)  List the types of Programmable logic array.

18)  Difference between PROM & EPROM.

19)  State the difference between primary and secondary memory.

20)  Draw the structure of Von-Neumann machine.

21)  List the advantages of Integrated Circuits.

22)  Define basic information types.

23)  Draw the IEEE format for single-precision and double-precision floating point numbers.

24)  List the types of operand.

25)  What do you mean by fixed point numbers?

Part – B

1. Explain in detail about Fixed Point Numbers 
2. Explain the basic functional units of a computer with neat sketch.
3. Discuss about the various instruction formats.
4. Explain brief history of computer.
5. List the rules for floating point addition and subtraction. Explain with example.
6. Explain the various instruction types.
7. Write a short note on

i.                    Program Counter

ii.                  Accumulator        

iii.                Instruction Register

iv.                Stack Pointer

8. Assuming 8-bit word length, express the following decimal numbers in:

i.                    Sign magnitude representation.

ii.                  One’s complement

iii.                Two’s complement form

a.       -39      b. -120

9. Explain floating point numbers and operations
10. Describe the IEEE standards for single precision and Double precision floating point numbers.

Unit II

        Part – A

1)      Convert the following pairs of decimal numbers to 5-bit, signed, 2’s-complement, binary numbers and add them.

a.       -14 and 11

b.      5 and 10

2)      Solve the following using 2’s complement arithmetic.

a.       Add 46 and 18

b.      Subtract 34 from 52

3)      List the rules for Binary Addition.

4)      State the conditions when an integer overflow occurs.

5)      State the Robertson algorithm for 2’s complement multiplication.

6)      Mention the various approaches for reducing the delay in adders.

7)      Design a 4-bit carry look ahead logic.

8)      Differentiate between conventional shift right and arithmetic shift right. Give example.

9)      Using sign extension of negative multiplicand simulate -12 X +10.

10)  Give the booth multiplier recoding table.

11)  Convert 11010 into bit pair recoding.

12)  State the algorithm for non-restoring division.

13)  List the advantages of 1’s complement subtraction

14)  Write the booth multiplication process of -19 X 4.

15)  List out the various rules for floating point multiplication.

16)  State the algorithm for restoring division.

17)  List out the various rules for floating point division.

18)  Draw the logic diagram for addition operation.

19)  Which number representation method is mostly used in today’s computers? Why?

20)  Draw the block diagram of the full-adder along with truth table.

21)  Draw the circuit arrangement for binary division.

22)  Write the manual multiplication process of 14 X 7.

23)  Generate the multiplier bit-pair recoding of -6.

24)  List out the various methods of truncation.

25)  What is meant by mantissa? Give example.

Part – B

1)      Explain briefly about addition and subtraction of signed numbers.

2)      State the principle of operation of a carry look ahead adder. Explain with a neat sketch.

3)      Explain the hardware for implementation of positive number multiplication.

4)      Draw the flowchart for implementing booth’s algorithm and multiply -13 and 11.

5)      With an example describe the process of carry save addition.

6)      Explain with an example the restoring division technique.

7)      Describe the IEEE standard for single-precision and double-precision floating point numbers.

8)      State the non-restoring division technique. Simulate the same for 20÷8.

9)      Describe in detail the hardware for implementation of signed operand multiplication.

10)   Explain the Robertson algorithm for 2’s complement multiplication.

Unit III

        Part – A

1)      What do you mean microoperation.

2)      What are the basic tasks of control unit.

3)      Define control memory

4)      Give the microoperation s for interrupt cycle.

5)      List out the basic operations performed by a processor.

6)      Draw the block diagram for PLA.

7)      We wish to transfer the contents of register R₁ to register R₄. How can you accomplish this by using the concept of register transfer?

8)      In a memory read operation, consider the instruction MOV (R₂), R₂. Give the actions needed to execute this instruction.

9)      Give the microoperations for Fetch cycle.

10)  Draw the block diagram hardwired control unit organization.

11)  Give the necessity for grouping of control signals.

12)  Show the structure of a 4-stage instruction pipeline.

13)  State the relative advantages of microprogrammed control over hardwired control.

14)  Draw the implementation of one-bit register.

15)  List out the various techniques used for grouping of control signals.

16)  Mention the various approaches used to deal with conditional branching.

17)  What do you mean by bit-slicing.

18)  List out the features of Bit Slicing.

19)  Give the advantages of NanoProgramming.

20)  Compare hardwired control unit and microprogrammed control unit.

21)  What are the design considerations of microprogram sequencer?

22)  What do you mean by instruction pipelining.

23)  In the microprogrammed control unit, the microprogram counter is incremented every time a new microinstruction is fetched from the microprogram memory, except some situations. Mentions those situations.

24)  State the advantages of delayed branching.

25)  What is the necessity of branching.

Part – B

1)      With neat sketch explain the organization of CPU.

2)      Explain the sequences of operations needed to perform following processor functions.

a.       Fetching a word from memory.

b.      Storing a word in memory.

c.       Performing an arithmetic or logical operation.

3)      Draw and explain typical hardwired control unit.

4)      Write a short note on pipeline performance.

5)      Discuss the organization of microprogrammed control unit. How are branches implemented here?

6)      Write a short note on nanoprogramming.

7)      Draw and explain the structure of a super scaling processing

8)      Explain different design approaches for hardwired control.

9)      Design a 4-stage pipeline and show how its performance improved over sequential execution.

10)  Explain the register organization of 16-bit sliced processor.

     

UNIT IV

                                                            Part – A

1. List the different characteristics of memory system.
2. How data is organized and formatted on the magnetic disk?
3. Differentiate SRAM and DRAM.
4. Write a note on memory  hierarchy.
5. Draw the typical organization of EDORAM..
6. What is data stripping?
7. Define memory interleaving.
8. Give the characteristics of magnetic disks.
9. Why is it necessary to implement virtual memory?
10. Define hit rate and miss rate.
11. Give an account on locality of reference.
12. What is meant by DDR-SDRAM? Mention its special features.
13. Compare EPROM and EEPROM.
14. List the various type of optical memory.
15. Draw the framework for virtual memory address translation.
16. Define memory latency and bandwidth.
17. Give the purpose of memory interleaving.
18. Draw the memory hierarchy.
19. What is cache coherency? Why is it necessary?
20. Discuss the relative advantages and disadvantages of the three mapping techniques used in cache memories.
21. How cache memory is used in reducing the execution time?
22. State the uses of TLB.
23. Compare non-preemptive and preemptive memory allocation..
24. Write a note on memory allocation.
25. List out the most common replacements algorithms.

Part – B

1)      Draw and explain Associative cache organization.

2)      With neat sketch explain the organization of synchronous DRAM.

3)      Draw the organization of bit cells in a memory chip and briefly explain semiconductor RAM memories?

4)      Explain the major design issues existing for enhancing performance of cache Memory.

5)      Draw and explain the virtual memory organization.

6)      Explain the major design issues existing for enhancing performance of cache Memory.

7)      Draw and explain the organizations of

a.       ROM

b.      PROM

c.       EPROM

8)      Write notes on

1)      CD-ROM

2)      DVD Technology.

9)      Explain in detail about various RAID levels.

10)  Discuss in detail about translation look-aside buffer.

Unit V

      Part – A

1)      Why I/O devices cannot be connected directly to the system bus?

2)      Define synchronous and asynchronous data transfer.

3)      Specify the use of interrupt in an operating system.

4)      What is the use of DMA?

5)      Draw the block diagram representing two-channel DMA controller.

6)      List out the three set of lines used in processor bus.

7)      Differentiate parallel interface and serial interface.

8)      Draw the diagram that represents different interface standards used in computer system.

9)       Write notes on USB interface.

10)  Mention the techniques possible for I/O operations.

11)  Mention the disadvantages of programmed I/O.

12)  Draw the block diagram of an I/O module.

13)  Define cycle-stealing.

14)  What is distributed arbitration?

15)  Summarize the sequence of events in handling an interrupt request from a single device.

16)  Distinguish between synchronous bus and asynchronous bus.

17)  List out the functions of an I/O interface.

18)  What is the use of target controller in SCSI?

19)  Compare asynchronous bus and synchronous bus.

20)  Draw the block diagram representing serial interface.

21)  Write down the use of interrupts in operating systems.

22)  What is the purpose of using interrupt mask?

23)  Write short notes about daisy chain approach.

24)  Draw the block diagram of two channel DMA controller.

25)  Differentiate between centralized arbitration and distributed arbitration. 

Part – B

 

1)      Describe the working principle of USB.

2)      Write  brief notes on following:

(i) Enabling and Disabling Interrupts

(ii) Handling Multiple Devices.

3)      Draw and explain the block diagram of I/ O system.

4)      Briefly explain the role of the processor in I/O.

5)      Explain in detail the concepts of Direct Memory Access.

6)      Draw and explain the interface circuits in detail.

7)      What is DMA? Explain the different types of DMA.

8)      Briefly explain the following:

(i) Controlling Device Requests

(ii) Use of Exceptions in Operating Systems.

9)      Briefly explain the Standard I/O Interfaces with neat sketch?

10)  What are the steps are needed to control the transfer of data from an external device to CPU?

                                           

VINAYAKA MISSIONS UNIVERSITY

AARUPADAI VEEDU INSTITUTE OF TECHNOLOGY, PAIYANOOR

&

VMKV ENGINEERING COLLEGE, SALEM

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

QUESTION BANK

SUBJECT: CONTROL SYSTEM

CLASS / SEM / DEPARTMENT: III YEAR / V SEM / ECE

REGULATION: 2006

(LINEAR GRAPH SHEET, POLAR GRAPH SHEET, SEMI LOG GRAPH TO BE PROVIDED)

UNIT I-CONTROL SYSTEM MODELLING

PART A

1. What is a control system?
2. Define Transfer function.
3. What are the characteristics of negative feedback?
4. What are the advantages and disadvantages of open loop system?
5. What are the advantages and disadvantages of closed loop system?
6. Distinguish between open loop and closed loop systems.
7. What is feedback?
8. What is a summing point?
9. Write the rule for elimination of a feedback loop in a block diagram.
10. What is signal flow graph?
11. What is a mixed node? How can it be eliminated?
12. Write the Mason’s Gain formula.

PART B

1. Write the differential equations governing the mechanical system shown in fig. and determine the transfer function.

2. Determine the transfer function Y₂(s)/F(s) of the system shown in fig.

 

3. Write the differential equations governing the mechanical rotational system shown in fig. Obtain the transfer function of the system.

4. Write the differential equations governing the mechanical rotational system shown in fig. and determine the transfer function θ(s)/T(s).

5. Derive the transfer function of an armature controlled dc motor.

6. The block diagram of a closed loop system is shown in the figure using the

block reduction technique determine the closed loop transfer function C(s)/R(s).

 

7. Convert the block diagram to signal flow graph and determine the transfer

function using mason’s gain formula.

8. Convert the block diagram to signal flow graph and determine the transfer

function using mason’s gain formula.

 

9. The block diagram of a closed loop system is shown in the figure. Using the 

block reduction technique determine the closed loop transfer function C(s)/R(s).

 

10. Write the rules for Block diagram reduction techniques.

UNIT – II - TIME RESPONSE ANALYSIS

PART – A

1. Define Peak Time
2. Define Peak Over Shoot.
3. Define Settling Time.
4. What is the order of a system?
5. Write the second order systems response.
6. How the system is classified depending on the value of damping?

7. The closed loop transfer function of second order system is C(s)  =         10 ______                                                                                        

                                                                                                           R(s)        s² + 6s + 10

           Determine the damping ratio and the natural frequency of oscillations.

8.  What is the type of damping in the system?

9.  What is steady state error?

10. What are generalized error coefficients?

      11.  Mention two advantages of generalized error constants over static error constants.

       12. What is a PID controller?

PART – B

1.      Name the test signals used in control system and write the expression for each signal and explain.

2.      Derive the expression for response of first order for unit step input.

3.      Explain the second order system and derive the expression for response of undamped second order system for unit step input.

4.      Explain the time domain specifications of control system.

5.      A positional control system with velocity feedback is shown in fig. What is the response of the system for unit step input.

6.      Obtain the response of unity feed back system whose open loop transfer function is G(s) = 4/s(s+5) and when the input is unit step.

7.  Explain PI, PD and PID controllers.

UNIT III - FREQUENCY RESPONSE ANALYSIS

PART A

1.      Define gain margin

2.      Define phase margin

3.      What is a Nicholas plot

4.      What are the advantage of polar plot

5.      Define polar plot

6.      Define bode plot

7.      What is cut off rate

8.      What is gain cross over frequency

9.      What is phase cross over frequency

10.  Define corner frequency

PART B

1.      Sketch Bode plot for the following transfer function and determine the system gain K for the gain cross over frequency to be 5 rad/sec G(s) = Ks²/(1+0.2s)(1+0.02s)

2.      The open loop transfer function of a unity feedback system is given by               G(s) = 1/s(1+s)(1+2s). Sketch the polar plot and determine the gain margin and phase margin.

3.       The open loop transfer function of a unity feedback system is given by               G(s) = 1/s² (1+s)(1+2s). Sketch the polar plot and determine the gain margin and phase margin.

4.      Explain the frequency domain specifications.

5.      Briefly explain any one of the frequency response plot. Write their advantages and disadvantages.

6.      Form a circle for every value of M using closed loop transfer function using unity feed back system.

7.      Plot the Bode diagram for the following transfer function and obtain the gain and phase cross over frequencies. G(s) = 10/s(1+0.4s)(1+0.1s)

UNIT  IV - STABILITY

PART A

1)      Define BIBO stability.

2)      What is the requirement for BIBO stability?

3)      How the roots of characteristics equation are related stability?

4)      What is the necessary condition for stability?

5)      What is Routh stability criterion?

6)      What is Nyquist stability criterion?

7)      Write the transfer function of Nyquist stability criterion?

8)      What is magnitude criterion?

9)      Distinguish between the concept of encircled and enclosed of Nyquist stability criterion?

10)  Define gain margin and phase margin.

PART B

1) Explain the Nyquist stability criterion for closed loop transfer function.

2) Using Routh criterion, determine the stability of the system represented by the characteristics equation, s⁴+8s³+18s²+16s+5=0. Comment on the location of the roots of characteristics equationcteristic equation.

3) Construct Routh array and determine the stability of the system represented by the

Characteristic equation s⁵+s⁴+2s³+2s²+3s+5 = 0. Comment on the location of the roots of characteristics equation. 

4) Construct Routh array and determine the stability of the system whose characteristics equation, s⁶+2s⁵+8s⁴+12s³+20s²+16s+16 = 0. Also determine the number of roots lying on the half of s-plane and on imaginary axis.

5) a) Write the rules for construction of root locus.

    b) Write the procedure of root locus.

6) Sketch the root locus of the system whose open loop transfer function is

    G(s) = K/s(s+2)(s+4). Find the value of K so that damping retio of closed loop  

     syatem is 0.5

UNIT V - COMPENSATION DESIGN

PART A

1.      What is the time domain specifications needed to design a control system?

2.      Write the necessary frequency domain specifications for design of a control system.

3.      What is the compensator? What are the different types of compensator?

4.      When the lag/lead/lag-lead compensation is employed?

5.      Write the transfer function of lag, lead and lag-lead compensator.

6.      What is difference between root locus and frequency response of a compensator?

7.      What is lag compensator? What are the characteristics of lag compensation?

8.      What is lead compensator? What are the characteristics of lag compensation?

9.      What is lag-lead compensator? What are the characteristics of lag compensation?

10.  What is relation between Фm and β in lag and lead compensator?

PART B

1)      Obtain the transfer function for an electrical lag network using lag compensator

2)      Write the frequency response of lag compensator.

3) Write the frequency response of lead compensator.

4) a) Expalin polar plot of lag compensator

    b) Expalin Bode plot of lag compensator

5) a) Write the limitations of lead compensator

    b) Derive the maximum lag angle of lag compensator

7) Write the procedure of lag-lead compensator on root locus and frequency domain method.

8) Write the realization of lag-lead compensator using electrical network.