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ECE :: Digital Electronics

  1. The digit F in hexadecimal system is equivalent to number __________ in decimal system.

  2. A.
    16
    B.
    15
    C.
    17
    D.
    8

  3. In level clocking the output can change

  4. A.
    on rising edge of clock cycle
    B.
    on falling edge of clock cycle
    C.
    during entire half cycle of the clock
    D.
    none of the above

  5. Which family of logic circuits uses field effect transistors?

  6. A.
    TTL
    B.
    CMOS
    C.
    Both LED and well as LCD
    D.
    None of the above

  7. An encoder converts decimal numbers to binary and other codes.

  8. A.
    True
    B.
    False

  9. Examine the following truth table. The product of sum from this truth table is

  10. A.
    (X + Y) (X + Y)
    B.
    (X + Y) (X + Y)
    C.
    (X + Y) (X + Y)
    D.
    (X + Y) (X + Y)

  11. K maps can be drawn

  12. A.
    only for 2 variables
    B.
    only for 3 variables
    C.
    only for 4 variables
    D.
    for any number of variables

  13. When a TTL is driving an CMOS gates it is necessary to ensure that

  14. A.
    VOL(for TTL) ≤ VIL (for CMOS) and V0H (for TTL) ≥ VIH (for CMOS)
    B.
    V0L (for TTL) ≥ VIL (for CMOS)
    C.
    V0H (for TTL) ≤ VIH (for CMOS)
    D.
    V0L (for TTL) ≥ VIL (for CMOS) and V0H (for TTL) ≤ VIH (for CMOS)

  15. Which of the following statement is correct?

  16. A.
    Decimal 9 is represented as 1011 in Excess-3 code
    B.
    Decimal 9 is represented as 1001 is BCD code
    C.
    Decimal 10 is represented as 1100 is Gray code
    D.
    Decimal 10 is represented as 1001 in binary code

  17. For emitter-couple logic, the switching speed is very high because

  18. A.
    negative logic is used
    B.
    the transistors are not saturated when conducting
    C.
    emitter-coupled transistors are used
    D.
    multi-emitter transistors are used

  19. Subroutines are used in larger programs not

  20. A.
    to increase the programming case
    B.
    to reduce storage equipment
    C.
    to reduce program extension time
    D.
    for ease of program testing at the program development time