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ECE :: Digital Electronics

  1. Out of 5 M x 8, 1 M x 16, 2 M x 16 and 3M x 8 memories, which memory can store more bits?

  2. A.
    5 M x 8
    B.
    2 M x 16
    C.
    3 M x 8
    D.
    1 M x 16

  3. A 6 bit ladder A/D converter has input 101001. The output is (assume 0 = 0 V and 1 = 10 V)

  4. A.
    4.23
    B.
    6.41
    C.
    5.52
    D.
    9.23

  5. A ripple counter has 4 bits and uses flip flops with propagation delay time of 25 ns. The maximum possible time for change of state will be

  6. A.
    25 ns
    B.
    50 ns
    C.
    75 ns
    D.
    100 ns

  7. A counter has a modulus of 10. The number of flip flops is

  8. A.
    10
    B.
    5
    C.
    4
    D.
    3

  9. The counter shown in the given figure is built using 4 -ve edge triggered toggle FFs. The FF can be set asynchronously when R = 0. The combinational logic required to realize a modulo-13 counter is

  10. A.
    F = Q4 Q3 Q2 Q1
    B.
    F = Q4 + Q3 + Q2 + Q1
    C.
    F = Q4 + Q3 + Q2 + Q1
    D.
    F = Q4Q3Q2Q1

  11. In the figure, the LED

  12. A.
    emits light when both S1 and S2 are closed
    B.
    emits light when both S1 and S2 are open
    C.
    emits light when only S1 and S2 is closed
    D.
    does not Emit light, irrespective of the switched positions

  13. A 4 bit ripple counter uses flip flops with propagation delay of 50 ns each. The maximum clock frequency which can be used is

  14. A.
    5 MHz
    B.
    10 MHz
    C.
    20 MHz
    D.
    25 MHz

  15. An AND gate has two inputs A and B and one inhibit input S. Out of total 8 input states, output is 1 in

  16. A.
    1 state
    B.
    2 states
    C.
    3 states
    D.
    4 states

  17. 26810 = __________ .

  18. A.
    10A16
    B.
    10B16
    C.
    10C16
    D.
    10D16

  19. In a JK Master slave flip flop

  20. A.
    both master and slave are positively clocked
    B.
    both master and slave are negatively clocked
    C.
    master is positively clocked and slave is negatively clocked
    D.
    master is negatively clocked and slave is positively clocked