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

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

Section A

Attempt any two questions.

1. What is combinational circuit? Design a combinational circuit with four inputs that represent a decimal digit in BCD and four output lines that generate the 1’s complement of the input binary patterns.

2. What is asynchronous counter? Design asynchronous counter that counts the sequence of 0-1-4-6-7 using T flip-flop.

3. Implement the Boolean function F(P,Q,R,S) = Σ (3,4,6,8,9,14) using:

   a. 8 to 1 multiplexer
   b. PLA
   c. Decoder

Section B

Attempt any eight questions.

4. Perform the following operations:

   a. (011101)₂ – (110011)₂ using 2’s complement
   b. (89334)₁₀ – (98654)₁₀ using 9’s complement.

5. If f(P,Q,R,S) = Σ(3,4,7,8,14) and g(P,Q,R,S) = Σ(1,6,9,13). Simplify using K-map and design the circuit using minimum number of NAND gates.

6. What is the drawback of RS Flipflop? Explain D Flip Flop in detail with a logic diagram, characteristics table, and characteristics equation.

7. Design a full subtractor with necessary tables and logic diagram.

8. What is shift register? Explain 4 bit SISO and PIPO with timing diagram.

9. Design an asynchronous mod 11 up counter using T flip flop.

10. How race condition in JK flipflop can be resolved? Explain.

11. What is decoder circuit? Design 3 to 8 decoder circuit.

12. Write short notes on:

    a. State Diagram
    b. Encoder
    c. Parallel Adder