Digital Logic 2069

Long Answer Questions:

Attempt any TWO questions. (2x10=20)

1. What is decoder? Implement the following using decoder.

(a) F (W X Y Z) = Σ (0,1,3,4,8,9,10)

(b) F (W X Y Z) = Σ (1,3,5,6,11,13,14)

2. What do you mean by asynchronous counter? Design a mod-6 synchronous counter using T flip-

flops.

3. Explain the Master-slave S-R flip-flop with logic diagram, truth table and timing diagram.

Short answer questions :

Attempt any eight questions : (8x5=40)

4. Design a half subtractor using only NOR gates.

5. Convert the following decimal numbers into hexadecimal and octal number.

(a) 220

(b) 1020

6. Design a multiplexer 4x1 using only universal gates.

7. What is J-K flip flop? Explain.

8. Write a procedure to reduce K-maps.

9. What are the various types of shift registers?

10. Draw a logic diagram of a 4 bit ripple counter using D-flip flop.

11. Differentiate between combinational logic and sequential logic. List some applications of sequential logic.

12. Explain the decimal adder.

13. Write short notes on :

(a) Programmable Logic Array

(b) Triggering at flip-flop

(c) Memory Unit