Quiz  /  Pn Junction Diode Class 12 MCQ Questions With Answers

  • 1. 
    The barrier voltage at a pn junction for germanium is about ………

  • o.7
  • o.3
  • 1

  • 2. 
    The most commonly used semiconductor in making solar cell:

  • Ge
  • Si
  • Both Ge and Si
  • GaAs

  • 3. 
    Junction diode which detects optical signals:

  • Photodiode
  • LED
  • Solar Cells
  • All of these

  • 4. 
    For making LEDs , materials should have :

  • Eg < 1.8eV
  • Eg = 1.8eV
  • Eg > 1.8eV
  • none of above

  • 5. 
    When a pentavalent impurity is added to a pure semiconductor, it becomes ………

  • insulator
  • ptype
  • n type

  • 6. 
    A semiconductor has ………… temperature coefficient of resistance.

  • positive
  • negative
  • zero

  • 7. 
    In the middle of the depletion layer of reverse biased pn juntion, the

  • electric field is zero
  • potential is zero
  • potential is maximum
  • electric field is maximum

  • 8. 
    Addition of trivalent impurity to a semiconductor creates many ……..

  • holes
  • free electrons
  • valence electrons

  • 9. 
    If the positive terminal of the battery is connected to the anode of the diode, then it is known as

  • Forward biased
  • b) Reverse biased
  • c) Equilibrium

  • 10. 
    Characterstic feature of LED

  • It is lightly doped pn junction diode
  • It is heavily doped pn junction diode
  • Doping has no role in its fabrication
  • None of these

  • 11. 
    The most commonly used semiconductor is ………..

  • Geranium
  • silver
  • carbon

  • 12. 
    Junction diode which works without any biasing

  • photodiode
  • Light emitting diode
  • Solar cell
  • All of these

  • 13. 
    The colour of light emitted by an LED

  • depends on its band - gap energy
  • Does not depend on band gap energy
  • Depends on forward biasing
  • Depends on intensity of light falling on it

  • 14. 
    Photodiode works under

  • Forward Bias
  • Reverse Bias
  • No biasing required
  • Both forward and reverse bias

  • 15. 
    A semiconductor has generally ……………… valence electrons.

  • 4
  • 3
  • 2
  • 0
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