+2 Physics Unit 9. Semiconductor Devices And Their Applications

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+2 Physics Unit 9. Semiconductor Devices And Their Applications

Prepared by P. ILAIYARAJA M. Sc. ,B. Ed. , PG ASST IN PHYSICS , GHSS, PANCHANATHIKKULAM EAST, NAGAI DT.   ; & www. Padasalai. Net


Questions and Answers
  • 1. 
    The electrons in the atom of an element which determine its chemical and electrical properties are called
    • A. 

      Valence electrons

    • B. 

      Revolving electrons

    • C. 

      Excess electrons

    • D. 

      Active electrons

  • 2. 
    In an N−type semiconductor, there are
    • A. 

      immobile positive ions

    • B. 

      Immobile negative ions

    • C. 

      Holes as majority carriers

    • D. 

      No minority carriers

  • 3. 
    The reverse saturation current in a PN junction diode is only due to
    • A. 

      Minority carriers

    • B. 

      Donor ions

    • C. 

      Majority carriers

    • D. 

      Acceptor ions

  • 4. 
    In the forward bias characteristic curve, a diode appears as
    • A. 

      An ON switch

    • B. 

      An OFF switch

    • C. 

      A high resistance

    • D. 

      A capacitor

  • 5. 
    Avalanche breakdown is primarily dependent on the phenomenon of
    • A. 

      Collision

    • B. 

      Recombination

    • C. 

      Doping

    • D. 

      Ionisation

  • 6. 
    The colour of light emitted by a LED depends on
    • A. 

      Type of semiconductor material

    • B. 

      The amount of forward current

    • C. 

      Its forward bias

    • D. 

      Its reverse bias

  • 7. 
    The emitter base junction of a given transistor is forward biased and its collector−base junction is reverse biased. If the base current is increased, then its
    • A. 

      Ic will increase

    • B. 

      Vcc will increase

    • C. 

      Ic will decrease

    • D. 

      VCE will increase

  • 8. 
    Improper biasing of a transistor circuit produces
    • A. 

      Distortion in the output signal

    • B. 

      Excessive heat at collector terminal

    • C. 

      Faulty location of load line

    • D. 

      Heavy loading of emitter current

  • 9. 
    An oscillator is
    • A. 

      An amplifier with feedback

    • B. 

      A convertor of ac to dc energy

    • C. 

      Nothing but an amplifier

    • D. 

      An amplifier without feedback

  • 10. 
    Since the input impedance of an ideal operational amplifier is infinite,
    • A. 

      Its input current is zero

    • B. 

      Its output resistance is high

    • C. 

      its output voltage becomes independent of load resistance

    • D. 

      it becomes a current controlled device

  • 11. 
    • A. 

      OR

    • B. 

      AND

    • C. 

      EXOR

    • D. 

      NAND

  • 12. 
    If the output (Y) of the following circuit is 1, the inputs A B C must be
    • A. 

      101

    • B. 

      110

    • C. 

      010

    • D. 

      100

  • 13. 
    • A. 

      (4)

    • B. 

      (3)

    • C. 

      (2)

    • D. 

      (1)

  • 14. 
    The Boolean expression ABC can be simplified as
    • A. 

      (4)

    • B. 

      (3)

    • C. 

      (2)

    • D. 

      (1)

  • 15. 
    In a Colpitt’s oscillator circuit
    • A. 

      Capacitive feedback is used

    • B. 

      Tapped coil is used

    • C. 

      No tuned LC circuit is used

    • D. 

      No capacitor is used