Home / ECE / Electronic Devices and Circuits :: Section 2

ECE :: Electronic Devices and Circuits

  1. The amount of photoelectric emission current depends on the frequency of incident light.

  2. A.
    True
    B.
    False

  3. When a p-n junction is forward biased

  4. A.
    the width of depletion layer increases
    B.
    the width of depletion layer decreases
    C.
    the majority carriers move away from the junction
    D.
    the current is very small

  5. The carriers of n channel JFET are

  6. A.
    free electrons and holes
    B.
    holes
    C.
    free electrons or holes
    D.
    free electrons

  7. The depletion layer around p-n junction in JFET consists of

  8. A.
    hole
    B.
    electron
    C.
    immobile charges
    D.
    none of the above

  9. Junction temperature is always the same as room temperature.

  10. A.
    True
    B.
    False

  11. The mean free path of conduction electrons in copper is about 4 x 10-8 m. For a copper block, find the electric field which can give, on an average, 1 eV energy to a conduction electron

  12. A.
    2.62 x 107 V/m
    B.
    2.64 x 107 V/m
    C.
    2.5 x 107 V/m
    D.
    2.58 x 107 V/m

  13. When a p-n-p transistor is properly biased to operate in active region the holes from emitter.

  14. A.
    diffuse through base into collector region
    B.
    recombine with electrons in base
    C.
    recombine with electrons in emitter
    D.
    none of the above

  15. Assertion (A): Silicon is preferred over germanium in manufacture of semiconductor devices.

    Reason (R): Forbidden gap in silicon is more than that in germanium.

  16. 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

  17. Assertion (A): A decrease in temperature increases the reverse saturation current in a p-n diode.

    Reason (R): When a diode is reverse biased surface leakage current flows.

  18. 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

  19. At room temperature a semiconductor material is

  20. A.
    perfect insulator
    B.
    conductor
    C.
    slightly conducting
    D.
    any of the above