Analog Electronics

31. The action of JFET in its equivalent circuit can best be represented as a

  1. Current controlled Current source
  2. Current controlled voltage source
  3. Voltage controlled voltage source
  4. voltage controlled current source

Correct answer: (D)
voltage controlled current source

32. Three identical amplifiers with each one having a voltage gain of 50,input resistance of 1KΩ & output resistance of 250 ,are cascadeD. The open circuit voltage gain of combined amplifier is

  1. 49dB
  2. 51dB
  3. 98dB
  4. 102dB

Correct answer: (C)
98dB

33. An ideal OP-AMP is an ideal

  1. Current controlled Current source
  2. Current controlled voltage source
  3. Voltage controlled voltage source
  4. voltage controlled current source

Correct answer: (B)
Current controlled voltage source

34. In a full-wave rectifier using two ideal diodes,Vdc & Vm are the dc & peak values of the voltage respectively across a resistive loaD. If PIV is the peak inverse voltage of the diode, then the appropriate relationships for this rectifier is.

  1. Vdc = Vm/π, PIV=2Vm
  2. Vdc = 2Vm/π, PIV=2vm
  3. Vdc = 2Vm/π, PIV=Vm
  4. Vdc = Vm/π, PIV=Vm

Correct answer: (B)
Vdc = 2Vm/π, PIV=2vm

35. The cascade amplifier is a multistage configuration of

  1. CC-CB.
  2. CE-CB
  3. CB-CC
  4. CE-CC

Correct answer: (B)
CE-CB

36. The current gain of a BJT is

  1. gm r0
  2. gm / r0
  3. gm rπ
  4. gm /rπ

Correct answer: (C)
gm rπ

37. The most commonly used amplifier in sample & hold circuits is

  1. A unity gain non-inverting amplifier
  2. A unity gain inverting amplifier
  3. An inverting amplifier with a gain of 10
  4. An inverting amplifiers with a gain of 100

Correct answer: (B)
A unity gain inverting amplifier

38. To prevent a DC return between source and load, it is necessary to use

  1. resistor between source and load
  2. inductor between source and load
  3. capacitor between source and load
  4. either

Correct answer: (C)
capacitor between source and load

39. Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in

  1. Only the temperature
  2. only the β of the transistor
  3. Both Temperature & β
  4. None of the above

Correct answer: (C)
Both Temperature & β

40. Voltage Series feedback also called series-shunt feedback) results in

  1. Increase in both input & output impedances
  2. Decreases in both input & output impedances
  3. Increase in input impedance & decreases in output impedance
  4. Decrease in input impedance & increase in output impedance

Correct answer: (C)
Increase in input impedance & decreases in output impedance

Previous
Page 4 of 5
Next
Copyright © EngineeringMCQ.com