Full Marks: 60
Pass Marks: 24
Time: 3 hours

Attempt any two questions: (2 x 10 = 20)

1. Draw a block diagram, truth table and logic circuit of 1x16 Demultiplexer and explain its working principle.
2. Design a 3 bit synchronous counter and explain it.
3. What is magnitude comparator? Design a logic circuit for 4 bit comparator and explain it.

Attempt any eight questions: (8 x 5 = 40)

4. Design a half subtractor circuit using only NAND gates.

5. Convert the following decimal numbers into Hexadecimal and Octal numbers:

   • (a) 504
   • (b) 250

6. Design an encoder using universal gates.

7. What do you mean by D-flip-flop?

8. What is sequential logic? What are the important features?

9. Simplify the Boolean function using K-Maps.

   F = X’yz + X’yz’ +Xy’z’ +Xy’z

10. Draw a parallel-parallel-out shift register and explain it.

11. Explain the 4 bit ripple counter.

12. Explain the programmable logic array.

13. Write short notes on :

    • (a) Asynchronous counter
    • (b) Multiplexers
    • (c) State reduction table