Digital Logic 2071
Long Questions:
Attempt any two questions: (2 × 10=20)
1. What are the various types of numbering system use in the digital logic? Explain. Convert the 3EC816 into different numbering system that you know.
2. Design the mod-6 asynchronous counter and explain with truth table.
3. What is demultiplexer? Draw its block diagram and explain its working principle.
Short Questions:
Attempt any eight questions: (8 × 5=40)
4. Convert the hexadecimal number 2BFC to binary and then to octal.
5. Proof the De-Morgan 1st and 2nd theorem with truth table and logic gates.
De-Morgans Theorem
De Morgan’s theorem is used to convert OR type of expression into AND type and vice-versa.It is further divided into two different types;
1st law:
It state that the total complement of sum is equal to the product of individual complement. i.e. (A+B)’=A’ ٠B’
Proof:
Input |
Output |
||
A |
B |
(A+B)’ |
A’ ٠B’ |
0 |
0 |
1 |
1 |
0 |
1 |
0 |
0 |
1 |
0 |
0 |
0 |
1 |
1 |
0 |
|
2nd law:
It state that the total complement of the product is equal to the sum of individual complement. i.e. (A٠B)’ =A’+B’
Proof:
Input |
Output |
||
A |
B |
(A٠B)’ |
A’+B’ |
0 |
0 |
1 |
1 |
0 |
1 |
1 |
1 |
1 |
0 |
1 |
1 |
1 |
1 |
0 |
0 |
6. Simplify, the following Boolean function using three variable K-map.
a) F(X,Y,Z) = ∑(0,3,2,5)
b) F(A,B,C) = ∑(0,2,4,5,6)
7. Simplify the Boolean expression.
prepare truth table to show that the simplified expression is correct or not?
8. Explain the PLA (Programmable Logic Array).
9. How JK flip flop can convert into a D-flip flop?
10. What do you mean by synchronous counter? Explain with truth table.
11. Draw a 3 to 8 decoder circuit and explain its operation.
12. Mention the difference types of shift register and explain.
13. Write short notes on:-
a) CMOS
b) Universal gates
c) Error detection code