Semiconductor Diode MCQ

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Semiconductor Diode MCQ

Semiconductor Diode MCQ, Semiconductor Diode Multiple Choice Questions, Multiple Choice Questions on Semiconductor Diode, PN Junction Based MCQ, Multiple Choice Questions on PN Junction Diode, GATE questions on Semiconductor of PN Junction Diode, Engineering MCQ, Electronics Device & Circuits MCQ

Multiple Choice Questions

Q.1. A crystal diode has ……..

  • one pn junction
  • two pn junctions
  • three pn junctions
  • none of the above

Answer: one pn junction

Q.2. A crystal diode has forward resistance of the order of ……..

  • Ω
  • none of the above

Answer: Ω

Q.3. If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is …….. biased.

  • forward
  • reverse
  • either forward or reverse
  • none of the above

Answer: forward

Q.4. The reverse current in a diode is of the order of ……..

  • kA
  • mA
  • μA
  • A

Answer: μA

Q.5. The forward voltage drop across a silicon diode is about ……..

  • 2.5 V
  • 3 V
  • 10 V
  • 0.7 V

Answer: 0.7 V

Q.6. A crystal diode is used as ……..

  • an amplifier
  • a rectifier
  • an oscillator
  • a voltage regulator

Answer: a rectifier

Q.7. The d.c. resistance of a crystal diode is …….. its a.c. resistance.

  • the same as
  • more than
  • less than
  • none of the above

Answer: less than

Q.8. An ideal crystal diode is one which behaves as a perfect …….. when forward biased.

  • conductor
  • insulator
  • resistance material
  • none of the above

Answer: conductor

Q.9. The ratio of reverse resistance and forward  resistance of a germanium crystal diode is about ……..

  • 1 : 1
  • 100 : 1
  • 1000 : 1
  • 40000 : 1

Answer: 40000 : 1

Q.10. The leakage current in a crystal diode is due to ……..

  • minority carriers
  • majority carriers
  • junction capacitance
  • none of the above

Answer: minority carriers

Q.11. If the temperature of a crystal diode increases, then leakage current ……..

  • remains the same
  • decreases
  • increases
  • becomes zero

Answer: increases

Q.12. The PIV rating of a crystal diode is …….. that of equivalent vacuum diode.

  • the same as
  • lower than
  • more than
  • none of the above

Answer: lower than

Q.13. If the doping level of a crystal diode is increased, the breakdown voltage ………

  • remains the same
  • is increased
  • is decreased
  • none of the above

Answer: is decreased

Q.14. The knee voltage of a crystal diode is approximately equal to ……..

  • applied voltage
  • breakdown voltage
  • forward voltage
  • barrier potential

Answer: barrier potential

Q.15. When the graph between current through and voltage across a device is a straight line, the device is referred to as ……..

  • linear
  • active
  • nonlinear
  • passive

Answer: linear

Q.16. When the crystal diode current is large, the bias is ……..

  • forward
  • inverse
  • poor
  • reverse

Answer: forward

Q.17. A crystal diode is a …….. device.

  • non-linear
  • bilateral
  • linear
  • none of the above

Answer: non-linear

Q.18. A crystal diode utilises …….. characteristic for rectification.

  • reverse
  • forward
  • forward or reverse
  • none of the above

Answer: forward

Q.19. When a crystal diode is used as a rectifier, the most important consideration is ……..

  • forward characteristic
  • doping level
  • reverse characteristic
  • PIV rating

Answer:  PIV rating

Q.20. If the doping level in a crystal diode is increased, the width of depletion layer ……..

  • remains the same
  • is decreased
  • is increased
  • none of the above

Answer: is increased

Q.21. A zener diode has ……..

  • one pn junction
  • two pn junctions
  • three pn junctions
  • none of the above

Answer: one pn junction

Q.22. A zener diode is used as ……..

  • an amplifier
  • a voltage regulator
  • a rectifier
  • a multivibrator

Answer: a voltage regulator

Q.23. The doping level in a zener diode is …….. that of a crystal diode.

  • the same as
  • less than
  • more than
  • none of the above

Answer: more than

Q.24. A zener diode is always ………. connected.

  • reverse
  • forward
  • either reverse or forward
  • none of the above

Answer: reverse

Q.25. A zener diode utilises …….. characteristic for its operation.

  • forward
  • reverse
  • both forward and reverse
  • none of the above

Answer: reverse

Q.26. In the breakdown region, a zener diode behaves like a ……… source.

  • constant voltage
  • constant current
  • constant resistance
  • none of the above

Answer: constant voltage

Q.27. A zener diode is destroyed if it ……..

  • is forward biased
  • is reverse biased
  • carries more than rated current
  • none of the above

Answer: carries more than rated current

Q.28. A series resistance is connected in the zener circuit to ……..

  • properly reverse bias the zener
  • protect the zener
  • properly forward bias the zener
  • none of the above

Answer: protect the zener

Q.29. A zener diode is …….. device.

  • a non-linear
  • a linear
  • an amplifying
  • none of the above

Answer: a non-linear

Q.30. A zener diode has …….. breakdown voltage.

  • undefined
  • sharp
  • zero
  • none of the above

Answer: sharp

Q.31. …….. rectifier has the lowest forward resistance.

  • solid state
  • vacuum tube
  • gas tube
  • none of the above

Answer: solid state

Q.32. Mains a.c. power is converted into d.c. power for ……..

  • lighting purposes
  • heaters
  • using in electronic equipment
  • none of the above

Answer: using in electronic equipment

Q.33. The disadvantage of a half-wave rectifier is that the ……..

  • components are expensive
  • diodes must have a higher power rating
  • output is difficult to filter
  • none of the above

Answer: output is difficult to filter

Q.34. If the a.c. input to a half-wave rectifier has an r.m.s. value of 400/ 2 volts, then diode PIV rating is ……..

  • 400/ 2 V
  • 400 V
  • 400 × 2 V
  • none of the above

Answer: 400 V

Q.35. The ripple factor of a half-wave rectifier is ……..

  • 2
  • 1.21
  • 2.5
  • 0.48

Answer: 0.48

Q.36. There is a need of transformer for ……..

  • half-wave rectifier
  • centre-tap full-wave rectifier
  • bridge full-wave rectifier
  • none of the above

Answer: centre-tap full-wave rectifier

Q.37. The PIV rating of each diode in a bridge rectifier is …….. that of the equivalent centretap rectifier.

  • one-half
  • the same as
  • twice
  • four times

Answer: the same as

Q.38. For the same secondary voltage, the output voltage from a centre-tap rectifier is …….. than that of bridge rectifier.

  • twice
  • thrice
  • four times
  • one-half

Answer: one-half

Q.39. If the PIV rating of a diode is exceeded, ……..

  • the diode conducts poorly
  • the diode is destroyed
  • the diode behaves as zener diode
  • none of the above

Answer: the diode is destroyed

Q.40. A 10 V power supply would use …….. as filter capacitor.

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

Answer: electrolytic capacitor

Q.41. A 1000 V power supply would use …….. as a filter capacitor.

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

Answer: paper capacitor

Q.42. The …… filter circuit results in the best voltage regulation.

  • choke input
  • capacitor input
  • resistance input
  • none of the above

Answer: choke input

Q.43. A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8 : 1, what is the peak load voltage ? Ignore diode drop.

  • 27.5 V
  • 86.5 V
  • 30 V
  • 42.5 V

Answer: 42.5 V

Q.44. The maximum efficiency of a half-wave rectifier is ………..

  • 40.6%
  • 81.2%
  • 50%
  • 25%

Answer: 40.6%

Q.45. The most widely used rectifier is ………..

  • half-wave rectifier
  • centre-tap full-wave rectifier
  • bridge full-wave rectifier
  • none of the above

Answer: bridge full-wave rectifier

Semiconductor Physics MCQ

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