Electronic Devices And Circuits Set 3

Electronics and Communication Engineering

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This set of Electronic Devices and Circuits Multiple Choice Questions & Answers (MCQs) focuses on Electronic Devices And Circuits Set 3

Q1 | A common-source amplifier is similar in configuration to which BJT amplifier?
  • common-base
  • common- collector
  • common-emitter
  • emitter- follower
Answer: common-emitter
Q2 | When transistors are used in digital circuits they usually operate in the
  • active region
  • breakdown region
  • saturation and cutoff regions
  • linear region
Answer: saturation and cutoff regions
Q3 | Which of the following elements are important in determining the gain of the system in the high-frequency region?
  • interelectrode capacitances
  • wiring capacitances
  • miller effect capacitance
  • all of the above
Answer: all of the above
Q4 | For audio systems, the reference level is generally accepted as                .
  • 1 mw
  • 1 w
  • 10 mw
  • 100 mw
Answer: 1 mw
Q5 | What is the normalized gain expressed in dB for the cutoff frequencies?
  • –3 db
  • +3 db
  • –6 db
  • –20 db
Answer: –3 db
Q6 | Which of the following configurations does not involve the Miller effect capacitance?
  • common-emitter
  • common-base
  • common- collector
  • all of the above
Answer: common-base
Q7 | When transistors are used in digital circuits they usually operate in the
  • active region
  • saturation and cutoff regions
  • breakdown region
  • linear region
Answer: saturation and cutoff regions
Q8 | A current ratio of IC/IE is usually less than one and is called
  • omega
  • beta
  • theta
  • alpha
Answer: alpha
Q9 | A transistor may be used as a switching device or as a:
  • tuning device
  • rectifier
  • fixed resistor
  • variable resistor
Answer: variable resistor
Q10 | Most of the electrons in the base of an NPN transistor flow:
  • into the collector
  • into the emitter
  • out of the base lead
  • into the base supply
Answer: into the collector
Q11 | The BJT is a device. The FET is a device.
  • bipolar, bipolar
  • bipolar, unipolar
  • unipolar, bipolar
  • unipolar, unipolar
Answer: bipolar, unipolar
Q12 | The Bode plot is applicable to
  • all phase network
  • minimum phase network
  • maximum phase network
  • lag lead network
Answer: minimum phase network
Q13 | For any inverting amplifier, the impedance capacitance will be                 by a Miller effect capacitance sensitive to the gain of the amplifier and the interelectrode capacitance.
  • unaffected
  • increased
  • decreased
  • none of the above
Answer: decreased
Q14 | The dc emitter current of a transistor is 8 mA. What is the value of re?
  • 320 Ω
  • 13.3 kΩ
  • 3.125 Ω
  • 5.75 Ω
Answer: 3.125 Ω
Q15 | An emitter-follower amplifier has an input impedance of 107 kΩ. The input signal is 12 mV. The approximate output voltage is (common-collector)
  • 8.92 v
  • 112 mv
  • 12 mv
  • 8.9 mv
Answer: 12 mv
Q16 | You have a need to apply an amplifier with a very high power gain. Which of the following would you choose?
  • common-collector
  • common-base
  • common-emitter
  • emitter- follower
Answer: common-emitter
Q17 | What is the most important r parameter for amplifier analysis?
  • rb′
  • rc′
  • re′
  • none of the above
Answer: re′
Q18 | A common-emitter amplifier has voltage gain, current gain, power gain, and input impedance.
  • high, low, high, low
  • high, high, high, low
  • high, high, high, high
  • low, low, low, high
Answer: high, high, high, low
Q19 | To analyze the common-emitter amplifier, what must be done to determine the dc equivalent circuit?
  • leave circuit unchanged
  • replace coupling and bypass capacitors with opens
  • replace coupling and bypass capacitors with shorts
  • replace vcc with ground
Answer: replace coupling and bypass capacitors with opens
Q20 | What is re equal to in terms of h parameters?
  • hre / hoe
  • (hre + 1) / hoe
  • hie – (hre / hoe)(1+ hfe)
  • hfe
Answer: hre / hoe
Q21 | The advantage that a Sziklai pair has over a Darlington pair is
  • higher current gain.
  • less input voltage is needed to turn it on.
  • higher input impedance.
  • higher voltage gain.
Answer: less input voltage is needed to turn it on.
Q22 | What is the device in a transistor oscillator?
  • lc tank circuit
  • biasing circuit
  • transistor
  • feedback circuit
Answer: transistor
Q23 | When the collector supply is 5V, then collector cut off voltage under dc condition is
  • 20 v
  • 10 v
  • 2.5 v
  • 5 v
Answer: 5 v
Q24 | The common base (CB) amplifier has a compared to CE and CC amplifier.
  • lower input resistance
  • larger current gain
  • larger voltage gain
  • higher input resistance
Answer: lower input resistance
Q25 | When a FET with a lower transconductance is substituted into a FET amplifier circuit, what happens?
  • the current gain does not change
  • the voltage gain decreases
  • the circuit disamplifies
  • the input resistance decreases
Answer: the voltage gain decreases
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