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ECE :: Digital Electronics

  1. A buffer is a device that isolates other devices. Typically a buffer has

  2. A.
    a high input impedance and a low output impedance
    B.
    a high input impedance as well as output impedance
    C.
    a low input impedance and a high output impedance
    D.
    a low input impedance as well as output impedance

  3. Which of the following is used as switch?

  4. A.
    J-K flip-flop
    B.
    Master slave J-K flip-flop
    C.
    T-flip-flop
    D.
    D-flip-flop

  5. In a positive edge triggered D flip flop

  6. A.
    D input is called direct set
    B.
    Preset is called direct reset
    C.
    Present and clear are called direct set and reset respectively
    D.
    D input overrides other inputs

  7. The first contribution to logic was made by

  8. A.
    George Boole
    B.
    Copernicus
    C.
    Aristotle
    D.
    Shannon

  9. Average latency time of magnetic tape memory is of the order of

  10. A.
    1 μ sec
    B.
    1 msec
    C.
    1 sec
    D.
    1 minute

  11. Which one of the following is loaded in the main memory by the bootstrap loader?

  12. A.
    System data
    B.
    User program
    C.
    BIOS
    D.
    Part of DOS

  13. In a NAND SR latch S = 0, R = 1 then

  14. A.
    Q = 0
    B.
    Q = 1, Q = 0
    C.
    it is race condition
    D.
    none of the above

  15. Microprocessors find applications in

  16. A.
    pocket calculators
    B.
    scientific instruments
    C.
    medical equipments
    D.
    all of the above

  17. The characteristic equation of flip-flop gives the next state QN + 1 in terms of present state QN and the inputs. Which one of the following is the characteristic equation of J - K flip-flop?

  18. A.
    QN+1 = JQN + KQN
    B.
    QN+1 = J + KQN
    C.
    QN+1 = KQN + JQN
    D.
    QN+1 = K + JQN

  19. If we need a device to shut off a few ampere current in a few nano seconds, the proper devices is

  20. A.
    VMOS
    B.
    CMOS
    C.
    BJT
    D.
    UJT