Electronic Devices and Circuit Theory-Oscillator Circuits

Electronic Devices and Circuit Theory-Oscillator Circuits
21. The twin-T oscillator produces a ________ response.
  • low-pass
  • high-pass
  • band-pass
  • band-stop
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22. What is the typical value of quality factor for crystal oscillators?
  • 20,000
  • 1000
  • 100
  • 10
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23. Which of the following improvements is (are) a result of the negative feedback in a circuit?
  • Higher input impedance
  • Better stabilized voltage gain
  • Improved frequency response
  • All of the above
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24. In the Wien bridge oscillator, which of the following is (are) frequency-determining components?
  • R1 and R2
  • C1 and C2
  • R1, R2, C1, and C2
  • None of the above
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25. A certain oscillator has a tap on the inductor in the tank circuit. This oscillator is probably
  • a Colpitts oscillator.
  • a Clapp oscillator
  • a crystal oscillator.
  • a Hartley oscillator.
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26. At parallel resonance, the impedance of a crystal is
  • minimum.
  • maximum.
  • equal
  • zero.
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27. Calculate the fr of a lead-lag network if R1 = R2 = 6.8 k, and C1 = C2 = 0.05 F.
  • 468 Hz
  • 4.68 kHz
  • 46.8 kHz
  • 468 kHz
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28. Which of the following is (are) feedback?
  • Voltage-series
  • Voltage-shunt
  • Current-series
  • All of the above
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29. What is the relationship between the series and parallel resonant frequencies of a quartz crystal?
  • They are equal.
  • Parallel resonant frequency is approximately 1 kHz higher than series resonant frequency.
  • Series resonant frequency is approximately 1 kHz higher than parallel resonant frequency.
  • none of the above
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30. An op-amp integrator has a square-wave input. The output should be
  • a sine wave.
  • a triangle wave.
  • a square wave
  • pure dc.
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