POKHARA UNIVERSITY

Level: Bachelor                                  Semester: Spring                                   Year: 2023

Programme: BBA/BI/TT/BCIS/BHCM/BHM                                              Full Marks: 100

Course: Digital Systems                                                                           Pass Marks: 45

Time: 3 hrs.

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

                                                                 Section "A"

                                                 Very Short Answer Questions

       Attempt all the questions. [10×2]

1. Define digital system and mention its advantages.

2. What is De-Morgan's Theorem? State and explain.

3. What will be the output of the X-NOR gate if inputs are different?

4. Write the BCD (8421) representation of decimal numbers 8956 and 3924.

5. If there are 88 outputs in a demultiplexer, then find the number of inputs and selector lines.

6. Draw a circuit diagram of SISO and PIPO.

7.Write a few points on Ultra large scale integration is the future.

8. Mention the advantage of Integrated circuits.

9. Draw the block diagram of ALU.

10. Define Flags. Mention its types.

Answers: https://onlinenotesnepal.com/very-short-answers-spring-2023-digital-system

                                                              Section " B "

                                                 Descriptive Answer Questions

         Attempt any six questions. [6 * 10]

11. Perform the following conversion

a) (34D.5A)16 =(?)16

b) (100110101)gray =(?)2

c) (344)10 =(?)8

d) (1156)8 =(?)16

12. What do you mean by Basic gates & Universal gates? Prove the universality of the universal gates.

13. What do you mean by SOP and POS functions? Convert the Boolean Function into standard form and draw the final circuit.

                     F = A'B + BC'D + A' B'C'D

14. Implement a full subtractor using half subtractor.

15. Simplify the given expression 

      F(ABCD) = ∑(0, 1, 2, 3, 7, 8, 9, 10, 11, 15) using k-map and realise the reduced expression using NAND Gate only.

16. Explain the operation of Parallel IN Serial Out (PISO) Shift Register alongwith its timing diagram.

17. Explain bus organization and processor organization.

                                                              Section "C"

                                                            Case Analysis

18. Mention the design procedure for the sequential circuit. Design a sequential circuit from the following state diagram using any flipflop of your choice. [20]