About Analog Electronics

Following are some of the multiple choice questions on the Analog Electronics with answers that will help the students in developing their knowledge.

Analog Electronics MCQ

1. Which of the following statements is false?

  • Push pull signals are equal and opposite in phase
  • Class AB operation cannot be used for a push pull audio power output phase
  • A push pull output transformer has a centre-tapped primary
  • All of the above

2. Negative feedback in an amplifier

  • Reduces gain
  • Increase frequency &phase distortion
  • Reduces bandwidth
  • Increases noise

3. A hole in a semiconductor is defined as

  • a free electron
  • the incomplete part of an electron pair bond
  • a free proton
  • a free neutron

4. MOSFET can be used as

  • Current controlled capacitor
  • voltage controlled capacitor
  • current controlled indicator
  • voltage controlled indicators

5. MOSFET can be used as a

  • Current controlled capacitor
  • Voltage controlled capacitor
  • Current controlled inductor
  • Voltage controlled inductors

6. What is an energy gap?

  • Space between two orbital shells
  • Energy band in which electrons can move freely
  • Energy level at which an electron can exist
  • None of the above

7. The diode current equation is not applicable in ____________

  • Forward biased state
  • Reverse biased state
  • Unbiased state
  • It is applicable in all bias states

8. In an OP-amp differentiator

  • The amplitude of output is proportional to rate of change of input
  • The amplitude of output is proportional to input
  • Output occurs when input is finite and constant
  • Polarity of input and output is the same

9. Anode is

  • Positive
  • Negetive
  • Chargeless
  • Neutral

10. The current gain of a bipolar transistor drops at high frequencies because of

  • Transistor capacitances
  • High current effects in the base
  • Parasitic inductive elements
  • The early effect

11. Which of the following oscillators is suitable for frequencies in the range of mega hertz?

  • RC phase shift
  • Wien bridge
  • Hartley
  • Both (a) and (c)

12. Thermal runaway is not possible in FET because as the temperature of FET increases

  • The mobility decreases
  • The transconductance increases
  • The drain current increases
  • None of the above

13. In a transistor leakage current mainly depends on

  • Doping of base
  • Size of emitter
  • Rating of transistor
  • Temperature

14. The cascade amplifier is a multistage configuration of

  • CC-CB
  • CE-CB
  • CB-CC
  • CE-CC

15. What will happen if doping of an intrinsic semiconductor with pentavalent impurity atom ?

  • Fermi level not change
  • Fermi level fall
  • Fermi level raises
  • All of the above

16. The early effect in a bipolar junction transistor is caused by

  • Fast turn-on
  • Fast turn-off
  • Large collector-base reverse bias
  • Large emitter-base forward bias

17. The current gain of a BJT is

  • gm r0
  • gm / r0
  • gm rπ
  • gm /rπ

18. In a CE amplifier the input impedance is equal to the ratio of

  • ac base voltage to ac base current
  • ac base voltage to ac emitter current
  • ac emitter voltage to ac collector current
  • ac collector voltage to ac collector current

19. A change in the value of the emitter resistance Re in a differential amplifier

  • Affects the difference mode gain Ad
  • Affects the common mode gain Ac
  • Affects both Ad and Ac
  • Does not effect either Ad and Ac

20. In a CB amplifier the maximum efficiency could be

  • 99%
  • 85%
  • 50%
  • 25%

21. In a half wave rectifier, the input sine wave is 250sin100 ᴨt Volts. The output ripple frequency of rectifier will be __________

  • 100 Hz
  • 200 Hz
  • 50 Hz
  • 25 Hz

22. A 10 V power supply would use which filter capacitor?

  • paper capacitor
  • electrolytic capacitor
  • mica capacitor
  • air capacitor

23. An RC oscillator uses

  • one RC combination
  • two RC combinations
  • at least three RC combinations
  • either (a) or (b)

24. Which power amplifier can deliver maximum load power?

  • Class A
  • Class AB
  • Class B
  • Class C

25. In a common emitter, unbypassed resister provides

  • voltage shunt feedback
  • current series feedback
  • negative voltage feedback
  • positive current feedback

26. Colpitts oscillator consists of _____ capacitor and _______ inductor

  • one, one
  • one, two
  • two, two
  • two, one

27. The abbreviation PIV in the case of a diode stands for ____________

  • Peak Inferior Voltage
  • Problematic Inverse Voltage
  • Peak Inverse Voltage
  • Peak Internal Voltage

28. The bandwidth of an RF tuned amplifier is dependent on

  • Q –factor of the tuned o/p circuit
  • Q –factor of the tuned i/p circuit
  • Quiescent operating point
  • Q-factor of the o/p and i/p circuits as well as quiescent operating point

29. An exponential amplifier has diode in feedback path.

  • True
  • False

30. The threshold voltage of a diode at Antarctica and India were found to be V1 and V2 respectively. Which of the following relations between V1 and V2 hold good?

  • V1 > V2
  • V1 = V2
  • V1 < V2
  • Can’t be determined

31. To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use

  • surge resistor
  • surge inductor
  • surge capacitor
  • both (a) and (b)

32. Reverse collector saturation current ICBO is __________

  • Collector current when emitter current is zero
  • Collector current when base current is zero
  • Same as reverse saturation current
  • Collector current when either emitter or base current is zero

33. The coupling capacitor in amplifier circuits

  • affects dc biasing
  • does not affect dc biasing
  • affects dc biasing to some extent
  • both (a) and (c)

34. The effective channel length of a MOSFET in a saturation decreases with increase in

  • Gate voltage
  • Drain voltage
  • Source voltage
  • Body voltage

35. For high frequencies a capacitor like

  • an open circuit
  • a short circuit
  • either open circuit or short circuit
  • none of the above

36. Which of the following power amplifiers has highest efficiency?

  • Class A
  • Class AB
  • Class B
  • Class C

37. The input voltage for starting oscillations in an oscillator is caused by

  • negative feedback
  • positive feedback
  • noise voltage in resistors
  • a special generator

38. In a push pull circuit

  • each transistor conducts for 180°
  • each transistor conducts for more than 180° but less than 360°
  • each transistor conducts for less than 180°
  • the period of conduction of each transistor depends on circuit configuration

39. In a half wave diode rectifier circuit the current flows in the load circuit for

  • 90° in each cycle
  • 180° in each cycle
  • 270° in each cycle
  • 360° in each cycle

40. How is BJT used as a faster switch?

  • By operating it in the saturation and cut-off region
  • By operating it in the active and cut-off region
  • By using it in strong saturation
  • By decreasing its ON resistance

41. The encapsulation of transistor is necessary for

  • Preventing radio interference
  • Preventing photo-emission effects
  • Avoiding loss of free electrons
  • Mechanical ruggedness

42. What is the condition if no external potential energy is applied to the PN junction then diode ?

  • Forward biased
  • Reversed biased
  • Zero Bias
  • None of These

43. A buffer amplifier should have

  • low input impedance and high output impedance
  • high input impedance and high output impedance
  • high input impedance and low output impedance
  • low input impedance and low output impedance

44. The units of transistor h parameters h11 and h22 are

  • Same
  • Different

45. Whenever load is coupled class A amplifier through transformer efficiency

  • Increases
  • Decreases
  • Nothing happen

46. In a CE amplifier drives a low load resistance directly the result will be

  • overloading of amplifier
  • underloading of amplifier
  • overloading or underloading of amplifier depending on circuit
  • none of the above

47. The ideal characteristics of a stabilizer is

  • constant output voltage with low internal resistance
  • constant output current with low internal resistance
  • constant output voltage with high internal resistance
  • constant internal resistance and constant output current

48. The dissipation at the collector is in the quiescent state and increases with excitation in the case of a

  • class A series fed Amplifier
  • class A transistor coupled Amplifier
  • class AB amplifier
  • class B amplifier

49. In an amplifier the voltage gain is the ratio of

  • output voltage and emitter resistance
  • output voltage and input current
  • output voltage and input voltage
  • none of the above

50. The value of parameter re used in re transistor model

  • increases with increase in temperature
  • decreases with increase in temperature
  • is not affected by increase in temperature
  • either (b) or (c)

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