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Home ‣ Electronics and Communication Engineering ‣ Radio Receivers Comments
  • Question

  • A heterodyne frequency changer is called a


  • Options
  • A. Modulator
  • B. Mixer
  • C. Demodulator
  • D. Frequency translator

  • Correct Answer
  • Mixer 

    • Radio Receivers problems

    Search Results

    • 1. The output of a diode detector contains

    • Options
    • A. D.C. voltage
    • B. modulating signal
    • C. RF ripple
    • D. all of the above
      • Discuss
    • 2. Which of the following should be used in order to prevent overloading or the last IF amplifier in a receiver?

    • Options
    • A. Variable selectivity
    • B. Variable sensitivity
    • C. Double conversion
    • D. Squelch
      • Discuss
    • 3. RF amplifiers are used in radio receivers for

    • Options
    • A. improved image frequency rejection
    • B. improved rejection of adjacent unwanted signals
    • C. prevention of re-radiation of the local oscillator through the antenna of the receiver
    • D. all of the above
      • Discuss
    • 4. An unmodulated voltage 10 V effective is applied to a dioxide detector in which load resistance is 4 x 10-5 ohms. A micrometer shows that the rectified DC current in this resistance is 30 A. The input resistance of the detector is

    • Options
    • A. 114 kW
    • B. 336 kW
    • C. 384 kW
    • D. 455 kW
      • Discuss
    • 5. In a superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is

    • Options
    • A. 750 kHz
    • B. 990 kHz
    • C. 1650 kHz
    • D. 2100 kHz
      • Discuss
    • 6. Modulated carrier power in FM

    • Options
    • A. increases with modulating signal power
    • B. decreases with modulating signal power
    • C. is independent of the modulating signal power
    • D. none
      • Discuss
    • 7. When fs is the signal frequency and fi is the intermediate frequency, then image frequency fsi is given by

    • Options
    • A. fsi = fs - 2fi
    • B. fsi = fs + 2fi
    • C.
    • D.
      • Discuss
    • 8. As compared to tuned radio frequency receivers which of the following is the advantage of using superheterodyne receivers?

    • Options
    • A. High gain and better sensitivity
    • B. Better selectivity at high frequencies
    • C. Stability
    • D. Noise suppression
      • Discuss
    • 9. Padders are used in a receiver to

    • Options
    • A. discard the carrier
    • B. facilitate tracking
    • C. filter the input signal
    • D. suppress noise
      • Discuss
    • 10. Most popular IF for receivers tuning to 540 to 1650 kHz is

    • Options
    • A. 433 kHz
    • B. 455 kHz
    • C. 545 kHz
    • D. 555 kHz
      • Discuss

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