Chapter-1
Q1. What is meant by analog and digital baseband signals ?
Q2. What is baseband transmission and give its disadvantages ?
Q3. Explain the need of modulation.
Q4. What are the advantages of using modulation technique ?
Q5. Define (i)Amplitude modulation (ii) Frequency modulation.
Q6. State and explain the concept of bandwidth.
Q7. what is the difference between simplex, half duplex and duplex systems, also give its examples.Give the Importance of communication.
Q8. what is the difference between wire communication and wireless communication.
Q9. State applications of wire and wireless communication.
Q10. What is electronic communication ?
Q11. Give simplex mode of data transmission also give the example.
Q12. What is analog signal and digital signal ?
Q13. Define modulation , frequency and wavelength.
Q14. Give the classification of AM systems.
Q15. State the expression for an AM wave.
Q16. What is the transmission bandwidth of AM?
Q17. Define Modulation Index?State the expression for modulation index?
Q18. Sketch the frequency spectrum of AM wave?
Q19. What are the disadvantages of amplitude modulation ?
Q20. Draw the waveform of AM wave?Draw frequency spectrum of AM wave and show how B.W. is calculated.
Q21. Explain the concept of sidebands?What is the importance of sidebands ?
Q22. Explain how in AM wave, all the information is contained in only the sidebands ?
Q23. Define FM and draw the necessary waveforms to explain it.
Q24. State the equation for FM wave.
Q25. Define angle modulation.
Q26. What is the bandwidth required for frequency modulation ?
Q27. Why frequency multipliers are used in transmitters ?
Q28. Explain with neat schematic diagram the operation of the basic communication system.
Q29. State and explain the applications of communication system.
Q30. Write a note on Electromagnetic spectrum and its applications in communication field.
Q31. What are the applications of following frequency bands in communication field
(i) MF (ii) UHF (iii) VHF
Q32. Write a brief note on Noise.
Q33. What is half and full duplex mode of transmission ? Give examples.
Q34. Explain analog mode of transmission with example.
Q35. Explain digital mode of transmission with example.
Q36. List the different frequency bands and their corresponding frequencies.
Q37. Draw and explain the electromagnetic spectrum.
Q38. State the different frequency bands and give their application.
Q39. State the expression for the spectrum of an AM wave and plot it.
Q40. Give the advantages, disadvantages and applications of AM.
Q41. Give the mathematical interpretation of amplitude modulated wave.
Q42. Draw and explain the block diagram of AM transmitter.
Q43. Differentiate between low level modulation and high level modulation.
Q44. Explain the difference between phase modulation and frequency modulation.
Q45. Audio equalizer is essential in case of Armstrong method of FM generation. Justify.
Q46. Justify FM is called a constant B.W. system.
Q47. State different methods of FM generation.
Q48. Define
l. Deviation ratio 2.Maximum deviation ratio. 3.Modulation index 4. Frequency deviation.
Q49. In a FM signal, which sideband frequencies are significant ?
Q50. Give the advantages and disadvantages of FM systems ?
Q51. Write note on Drawbacks of TRF receiver
Q52. How constant intermediate frequency is obtained in a superHeterodyne receiver. Explain.
Q53. Draw the block diagram of a superHeterodyne radio receiver and explain, waveforms at output of each block
Q54. List the type of electronic communication on the basis of type of transmission media.
Q55. Explain the necessity of modulation in electronics communication system with the help of -
(1) Height of antenna
(2) Mixing of various signals in common path.
Q56. Describe modulation index with waveform, if the modulating voltage of 5 volts is modulated with 7 volts of carder. Calculate % m.
Q57. Draw and explain the working of a simple diode detector. Also draw input and output waveforms if an over modulated waveform is given as the input.
Q58. Draw the block diagram of an FM receiver and explain the working.
Q59. Explain with the help of neat waveforms, the operation of the quadrature FM detector. State its applications.
Q60. Give the basic difference between AM receiver and FM receiver?
Q61. List the type of electronic communication on the basis of type of transmission media.
Q62. Give the frequency range for the following CCIR designation
(1) ELF (2) VLF (3) VHF (4) UHF
Q63. Draw an Amplitude modulated wave and label it.
Q64. Describe amplitude modulation and amplitude demodulation with the help of suitable waveforms.
Q65. Draw a Schematic block diagram of high level AM transmitter and label it.
Q66. Which RF range is most suitable for FM transmission?
Q67. Mention the typical value of bandwidth in FM.
Q68. Define the following terms in FM
(1) Carrier Swing. (2) Bandwidth
Q69. State with the help of diagram, what types of modulation takes place due to the variation of three parameters of sine wave.
Q70. Define modulation.
Q71. Draw a schematic block diagram of high level AM transmitter and label it.
Q72. State four methods of FM generation.
Q73. Draw the block diagram of an Armstrong (indirect) FM transmitter.
Q74. Draw schematic block diagram of AM low level transmitter and explain the function of each block.
Q75. List the basic function of a radio transmitter and a radio receiver.
Q76. Draw the block diagram of an Armstrong (indirect) FM transmitter.
Q77. Draw a schematic diagram of FM slope detector and explain its operation.
Q78. List the type of electronic communication on the basis of type of transmission media.
Q79. What is the bandwidth of modulated signal ? What it is significant factor?
Q80. Give the meaning of each term given in the following expression
Ptotal = Pcarrier (1 + m2/2)
Q81. Calculate the carrier power consumed if total power is 10 W for 50% modulation.
Q82. Draw and explain simple slope FM detector. Mention its merits and demerits
Q83. Define frequency deviation and write the practical values of maximum frequency deviation for commercial and radio broadcasting system.
Q84. State with the help of diagram, what type of modulation take place due to the variation of three parameters of sine wave.
Q85. How many side bands are in FM ? Why ?
Q86. What Is detector? With circuit diagram explain AM diode detector.
Q87. Explain working principle of basic communication system with block diagram.
Q88. Give the frequency range for VHF band. Give its applications.
Q89. Define modulation index of AM. calculate the total power if a 500 W carrier is modulated to a depth of 80%.
Q90. Define modulation index in FM and explain how does it affect the bandwidth required for FM channel.
Q91. Compare low level modulation and high level modulation.
Q92. Write the mathematical equation of FM. State disadvantages of FM over AM.
Chapter-2
Q1. Define radiation and propagation.
Q2. What is an EM wave?
Q3. Define polarization.
Q4. What is a wave front ?
Q5. Define a transverse EM wave.
Q6. Define attenuation and absorption.
Q7. Define diffraction, refraction.
Q8. State the frequency ranges for ground, sky and space wave propagations.
Q9. Define ground waves.
Q10. State advantages and disadvantages of ground wave propagation.
Q11. State applications of ground wave propagation.
Q12. Define ionosphere.
Q13. Explain the principle of sky wave propagation.
Q14. State advantages of sky wave propagation.
Q15. What are the applications of sky wave propagation ?
Q16. What is fading ?
Q17. Explain the principle of space wave propagation.
Q18. Define line of sight distance.
Q19. Define optical horizon and radio horizon.
Q20. State advantages of space wave propagation.
Q21. State disadvantages of space wave propagation?
Q22. What are the applications of space wave propagation ?
Q23. Define duct propagation.
Q24. What is tropospheric scatter propagation ?
Q25. Explain the following terms
(i) Ground wave and sky wave
(ii) Skip zone and skip distance
(iii) Actual height and virtual height
(iv) Critical frequency and maximum usable frequency.
Q26. Discuss the following anomalous propagation phenomena
(i) Sporadic E-layer
(ii) Duct propagation
iii) Troposcatter propagation
Q27. Explain ground wave propagation.
Q28. Describe the strata of the ionosphere and their effects on sky wave propagation. Explain why is this propagation generally better at night than during the day.
Q29. Explain briefly the mechanism of propagation. Give the approximate frequency and distance ranges of each and list the limitations of each of the modes of propagation.
Q30. In respect to sky wave propagation explain the following terms
1. Virtual height
2. MUF
3. Skip distance
4. Critical frequency
Q31. Write short notes on
A. Diversity reception
B. Tropospheric scatter propagation.
Q32. Describe line of sight propagation for Electromagnetic waves.
Q33. Explain why reception for HF band is better at night time.
Q34. State different radio frequency bands used in communication.
Q35. Differentiate between the sky waves and ground waves.
Q36. Explain in brief duct propagation.
Q37. What is fading ? What are its causes ?
Q38. What are electromagnetic waves ?
Q39. Explain, electromagnetic waves are transverse waves.
Q40. Define plane of polarization.
Q41. Define horizontally and vertically polarized waves.
Q42. What are ground waves and sky waves ?
Q43. Write note on wave propagation with ground waves.
Q44. Compare virtual height and actual height with respect to sky wave propagation.
Q45. State the meaning of fading. List its major causes.
Q46. Draw a sketch showing tropospheric scatter and explain its basic principle.
Q47. State the meaning of angle of tilt. How does it effect the field strength at a distance from a transmitter ?
Q48. With the help of figure describe virtual height.
Q49. State the meaning of the terms
(I) Propagation
(II) Polarization
Q50. Explain why ionospheric conditions vary with time of day, month of year and so on.
Q51. Describe various layers of Ionosphere
Q52. State the meaning of following terms
(a) Reflection (B) Refraction-
Q53. What factor affect the critical frequency for skip distance ?
Q54. State the meaning of electromagnetic wave and transverse waves.
Q55. State the meaning of fading. List its major causes.
Q56. Explain space wave propagation with suitable diagram.
Q57. State the meaning of electromagnetic wave and transverse wave.
Q58. Describe ground wave propagation with neat sketch.
Q59. what factor affect the critical angle for space wave propagation ?
Q93. Explain the concept of actual height and virtual height.
Q94. With neat sketch explain ionospheric wave propagation.
Q95. what is space wave propagation ? what is its disadvantage ? ,State its applications.
Q96. Explain in brief fading and critical frequency.
Q97. Define the following terms w wave propagation.
(1)Virtual height (2)Critical frequency (3)Maximum usable frequency (4)skip distance.
Q98. List features of Ground Wave Propagation.
Q99. Draw the diagram of ionosphere with distance and thickness of each layer.
Chapter-3
Q1. Give the elements for pulse communication system.
Q2. Define pulse modulation ? Give the types of pulse modulation.
Q3. Define Nyquist and Nyquist interval ?
Q4. Define
1. Pulse Amplitude Modulation (PAM).
2. Pulse Width Modulation (PWM).
3. Pulse Position Modulation (PPM).
Q5. What is quantizing noise ?
Q6. Define companding, encoding.
Q7. State the applications of PCM signals ?
Q8. Explain Nyquist rate.
Q9. Explain why is companding done in POM.
Q10. What are the advantages of ADM , DM?
Q11. State the types of distortions observed in a DM system.
Q12. What is granular noise ?
Q13. Explain the principles of Time Division Multiplexing.
Q14. Why is It necessary to use time division multiplexing while transmitting PAM signals ?
Q15. Why is synchronization needed in TDM system ?
Q16. Describe the multiplexing hierarchy for an FDM system.
Q17. What is FDM ? Where is it used ?
Q18. What Is TDM ? How is it different from FDM ?
Q19. What Is meant by signaling rate ?
Q20. Define the term “Frame” In case of TDM.
Q21. What type of modulation is used in FDM ?
Q22. Does FDM need synchronization 7
Q23. What are the advantages and disadvantages of FDM system 7
Q24. How is the “information transmitted in a PCM system
Q25. What is quantization ?
Q26. What is quantization error ? What is Its maximum value 7
Q27. How to reduce the quantization error?
Q28. Why is companding used?
Q29. What information do you transmit in DM system ?
Q30. What is the signaling rate of a DM system ?
Q31. How is slope overload reduced in ADM?
Q32. Is the signal and noise separable in PCM ?
Q33. What is the difference between DM and ADM ?
Q34. State the advantages of ADM over DM.
Q35. Explain the need of continuous wave (CW) modulation.
Q36. What is the application of CW modulation systems ?
Q37. What is the communication medium used in such systems ?
Q38. State various CW modulation systems.
Q39. Represent ASK mathematically.
Q40. State the bandwidth requirement of ASK system.
Q41. State merits and demerits of BASK.
Q42. What is the maximum B.W. of BPSK system ?
Q43. How many phases are transmitted in QPSK
Q44. What is the phase difference between the adjacent messages in QPSK ?
Q45. What are advantages of QPSK system
Q46. What is the typo of demodulation used for OPSK ?
Q47. State the expression for BFSK.
Q48. How is a message transmitted in BFSK ?
Q49. Write a note on sample and hold circuit.
Q50. Explain the generation of flat topped samples using sample and hold circuit.
Q51. Write short note on instantaneous sampling.
Q52. State and e sampling theorem.
Q53. Draw and explain the block diagram for generation of PDM signal.
Q54. Explain different techniques of practical sampling.
Q55. Explain the generation and reception of PAM signal.
Q56. Explain transmission and reception of PWM signals.
Q57. Differentiate between PAM, PWM and PPM system.
Q58. Explain the delta modulation system. What is slope overload ?
Q59. Compare PAM, PWM and PPM.
Q60. Compare PCM, 1DM, ADM and DPCM.