CHAPTER3-QUIZ (1).pdf

EE74 FUNDAMENTALS OF ELECTRONIC COMMUNICATION CHAPTER 3: Amplitude Modulation Fundamentals Instruction: Encircle the letter of the correct answer. NAME: _________________________ SECTION: ______________ 1. What is the main purpose of amplitude modulation in co...

EE74 FUNDAMENTALS OF ELECTRONIC COMMUNICATION CHAPTER 3: Amplitude Modulation Fundamentals Instruction: Encircle the letter of the correct answer. NAME: _________________________ SECTION: ______________ 1. What is the main purpose of amplitude modulation in communication systems? A. Increase frequency B. Transmit data over long distances C. Improve sound quality D. Decrease bandwidth 2. In amplitude modulation, which characteristic of the carrier wave is varied? A. Frequency B. Phase C. Amplitude D. Wavelength 3. Which of the following is true about the carrier signal in AM? A. It carries information directly. B. Its amplitude varies with the message signal. C. Its frequency changes with the message signal. D. It remains constant throughout. 4.The modulation index (m) in AM is defined as the ratio of the: A. Carrier frequency to modulating frequency B. Modulating signal voltage to carrier voltage C. Carrier voltage to modulating signal voltage D. Modulated frequency to carrier frequency 5.What happens when the modulation index exceeds 1 in AM? A. Overmodulation occurs B. The signal is perfectly modulated C. The signal is under-modulated D. No signal is transmitted 6. Which of the following is NOT an advantage of amplitude modulation? A. Simplicity of implementation B. Better noise immunity than FM C. Easy demodulation D. Ability to transmit over long distances 7. What are the sidebands in an AM signal? A. Upper and lower frequencies shifted from the carrier B. Distortion frequencies C. Noise frequencies D. Modulated carrier frequencies 8. In AM, how much of the total transmitted power is carried by the sidebands? A. 25% B. 50% C. 66.7% D. 100% 9.Which of the following is used to generate an AM signal? A. Oscillator B. Amplifier C. Modulator D. Filter 10.What is the frequency range of standard AM broadcast signals? A. 540 to 1600 kHz B. 88 to 108 MHz C. 30 to 300 kHz D. 3 to 30 MHz 11. An AM transmitter has a carrier power of 30 W. The percentage of modulation is 85 percent. Calculate the total power. A. 40.8 W B. 45 W C. 39.4 W D. 41.8 W 12. What AM stands for? A. Accurate modulation B. Antenna Modified C. Amplitude Modulation D. none of the above 13.Is a form of AM that offers unique benefits in some types of electronic communication? A. SSB B. DSB C. DSSC D. USB 14.This type of signal is referred to as a _________________ signal. A. SSB B. DSSC C. USBC D. FDD 15.Double-sideband suppressed carrier signals are generated by a circuit called a… A. Advance modulator B. Balanced modulator C. Amplitude modulator D. Frequency modulator 16.Codes designating signals described in this chapter are as follows: except A. DSB two sidebands, full carrier 5 = A3 B. SSB single sideband, suppressed carrier 5 = A3j C. Vestigial sideband TV 5 = A3c D. J3E SSB voice 17. What is the name of a signal that has both sidebands but no carrier? A. FAM B. DSB-SC C. SSB D. FSK 18. A sine wave at the carrier frequency, varying in amplitude. A. DSB signal B. SSB signal C. AM signal D. FD signal 19. An SSB transmitter has a 24-V dc power supply. On voice peaks the current achieves a maximum of 9.3 A. What is the value of PEP? A. 223.2 W B. 138.5 W C. 225 W D. 232.2 W 20. Which of the following is true about AM radio broadcasting? A. It uses higher bandwidth than FM. B. It is more immune to noise than FM. C. It can propagate over long distances via sky wave propagation. D. It has better sound quality than FM.  Answers key: 1. B 2. C 3. B 4. B 5. A 6. B 7. A 8. B 9. C 10. A 11. A 12. C 13. A 14. B 15. B 16. D 17. B 18. A 19. A 20. B