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ECE :: Electronic Devices and Circuits

  1. For a UJT if
    R1 = Resistor from emitter to the base 1
    R2 = Resistor from emitter to the base 2 and RBB = R1 + R2, then the intrinsic stand off ratio (η) is


  2. The kinetic energy of free electrons in a metal is (where k is de-Broglie wave number of the electrons)

  3. A.
    B.
    C.
    μk
    D.
    μk2

  4. Intrinsic concentration of charge carriers in a semiconductor varies as

  5. A.
    T
    B.
    T2
    C.
    T3
    D.
    T-2

  6. The dynamic resistance of a forward biased p-n diode

  7. A.
    varies inversely with current
    B.
    varies directly with current
    C.
    is constant
    D.
    is either constant or varies directly with current

  8. A thermistor is a

  9. A.
    thermocouple
    B.
    thermometer
    C.
    miniature resistance
    D.
    heat sensitive explosive

  10. When diodes are connected in series to increase voltage rating the peak inverse voltage per junction

  11. A.
    should not exceed half the breakdown voltage
    B.
    should not exceed the breakdown voltage
    C.
    should not exceed one third the breakdown voltage
    D.
    may be equal to or less than breakdown voltage

  12. Hall effect is observed in a specimen when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is

  13. A.
    normal to both current and magnetic field
    B.
    in the direction of current
    C.
    antiparallel to magnetic field
    D.
    in arbitrary direction

  14. In an ideal diode there is no breakdown, no __________ current, and no forward __________ drop.

  15. A.
    reverse, voltage
    B.
    forward, current
    C.
    forward, voltage
    D.
    reverse, current

  16. Silicon is not suitable for fabrication of light emitting diodes because it is

  17. A.
    an indirect band gap semiconductor
    B.
    direct band gap semiconductor
    C.
    wideband gap semiconductor
    D.
    narrowband gap semiconductor

  18. MOSFET can be used as a

  19. A.
    current controlled capacitor
    B.
    voltage controlled capacitor
    C.
    current controlled inductor
    D.
    voltage controlled inductor