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ECE :: Electronic Devices and Circuits

  1. The forbidden energy gap between the valence band and conduction band will be least in case of

  2. A.

     Metals

    B.

     Semiconductors

    C.

     Insulators

    D.

     All of the above


  3. For a NPN bipolar transistor, what is the main stream of current in the base region?

  4. A.

     Drift of holes

    B.

     Diffusion of holes

    C.

     Drift of electrons

    D.

     Diffusion of electrons


  5. Assertion (A): A JFET can be used as a current source.
    Reason (R): In beyond pinch off region the current in JFET is nearly constant.

  6. A.

     Both A and R are true and R is correct explanation of A

    B.

     Both A and R are true but R is not a correct explanation of A

    C.

     A is true but R is false

    D.

     A is false but R is true


  7. For a P-N diode, the number of minority carriers crossing the junction depends on

  8. A.

     Forward bias voltage

    B.

     Potential barrier

    C.

     Rate of thermal generation of electron hole pairs

    D.

     None of the above


  9. An electron in the conduction band

  10. A.

     Has higher energy than the electron in the valence band

    B.

     Has lower energy than the electron in the valence band

    C.

     Loses its charge easily

    D.

     Jumps to the top of the crystal


  11. What is the necessary a.c. input power from the transformer secondary used in a half wave rectifier to deliver 500 W of d.c. power to the load?

  12. A.

     1232 W

    B.

     848 W

    C.

     616 W

    D.

     308 W


  13. A thermistor is a

  14. A.

     Thermocouple

    B.

     Thermometer

    C.

     Miniature resistance

    D.

     Heat sensitive explosive


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

  16. A.

     Reverse, voltage

    B.

     Forward, current

    C.

     Forward, voltage

    D.

     Reverse, current


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

  18. A.

     Varies inversely with current

    B.

     Varies directly with current

    C.

     Is constant

    D.

     Is either constant or varies directly with current


  19. Each cell of a static Random Access memory contains

  20. A.

     6 MOS transistor

    B.

     4 MOS transistor, 2 capacitor

    C.

     2 MOS transistor, 4 capacitor

    D.

     1 MOS transistor and 1 capacitor