Electronic Devices-BJIt Amplifiers

Electronic Devices-BJIt Amplifiers
31. For a common-emitter amplifier, the purpose of the emitter bypass capacitor is
  • no purpose, since it is shorted out by RE.
  • to reduce noise.
  • to despike the supply voltage.
  • to maximize amplifier gain.
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32. For BJT amplifiers, the ________ gain typically ranges from a level just less than 1 to a level that may exceed 1000.
  • voltage
  • current
  • impedance
  • All of the above
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33. The loaded voltage gain of an amplifier is always more than the no-load level.
  • TRUE
  • FALSE
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34. What is the limit of the efficiency defined by = Po / Pi?
  • Greater than 1
  • Less than 1
  • Always 1
  • None of the above
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35. Which of the following techniques can be used in the sinusoidal ac analysis of transistor networks?
  • Small-signal
  • Large-signal
  • Small- or large-signal
  • None of the above
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36. The input impedance of a BJT amplifier is purely ________ in nature and can vary from a few ________ to ________.
  • resistive, ohms, megohms
  • capacitive, microfarads, farads
  • inductive, millihenrys, henrys
  • None of the above
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37. The ________ the source resistance and/or ________ the load resistance, the less the overall gain of an amplifier.
  • smaller, smaller
  • smaller, larger
  • larger, smaller
  • larger, larger
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38. A Darlington pair provides beta ________ for ________ input resistance.
  • multiplication, decreased
  • multiplication, increased
  • division, decreased
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39. A Darlington pair amplifier has
  • high input impedance and high voltage gain.
  • low input impedance and low voltage gain.
  • a voltage gain of about 1 and a low input impedance.
  • a low voltage gain and a high input impedance.
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40. A common-collector amplifier has high input impedance, good current gain, and a voltage gain of 1.
  • TRUE
  • FALSE
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