Tribhuvan University Digital Logic Board Exam Questions (2079)

Digital Logic (CSC116) 2079 BS Past Questions

TRIBHUVAN UNIVERSITY

INSTITUTE OF SCIENCE AND TECHNOLOGY

Bachelor Level: B.Sc. CSIT

Semester: First Semester

Subject: Digital Logic (CSC116)

Full Marks: 60 / 80

Pass Marks: 24 / 32

Candidates are required to give their answers in their own words as far as practicable.

Long Answer Questions

Attempt any Two questions.

1
Design the sequential circuit with respect to the following state diagram using T flip flops.
2
Implement $F=\Sigma(0,1,4,5,7)$ using: a. Multiplexer b. Decoder c. PLA
3
Differentiate between combinational circuit and sequential circuit. Design mod-10 synchronous counter using J-K flip flop. Show necessary truth tables and k-maps.

Short Answer Questions

Attempt any Eight questions.

4
Provide one example where shift left operation can be used. Explain serial-in-serial-out (SISO) register.
5
Carry out the following tasks: a. Perform 2's complement subtraction of $010110 - 100101$ b. Represent decimal number $10$ in its BCD form.
6
Derive the Boolean expression for sum and carry of half adder. Draw its combinational circuit. Implement it using only NOR gates.
7
Express $F'=(x+yz)'$ as a sum of min-terms.
8
Minimize the following Boolean function using K-map: $F(A,B,C,D)=\Sigma m(0,1,2,5,7,8,9,10,13,15)$.
9
What are the practical implications of down counter? Explain BCD ripple counter.
10
Design a combinational circuit with three inputs and one output. The output is $1$ when the binary value of the inputs is an even number.
11
Differentiate between ROM and PLA. Explain different types of ROM.
12
Write short notes on (Any two): a. Positive Logic b. $I^2L$ c. ASCII