# 17CS32 Analog and Digital Electronics Module 3

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## 17CS32 Analog and Digital Electronics Module 3

Here you can download the most important questions of module 3 of Analog and Digital Electronics.

1. What is a multiplexer? Design a 4 to 1 multiplexer using logic gates. Write the truth table and explain its working principle.

2. Construct 4:1 multiplexer using only 2:1 multiplexer.

3. Construct 8:1 multiplexer using only 2:1 multiplexer.

4. Design 16 to 1 multiplexer using 8 to 1 multiplexer and one 2 to 1 multiplexer.

5. Design 32 to 1 multiplexer using 16 to 1 multiplexer and one 2 to 1 multiplexer.

6. Mention the differences between decoder and demultiplexer.

7. Implement the following Boolean functions using 4:1 multiplexer (MUX):

(i) f(A, B, C, D) = Σm(0,1,2,4,6,9,12,14)  (ii) f(A, B, C) = Σm(1,3,5,6)

8. Realize the following Boolean function:

p = f(A, B, C, D) = Σm(0,1,5,6,7,10,15) using (i) 16:1 MUX (ii) 8:1 MUX (iii) 4:1 MUX

9. Design and implement BCD to excess-3 code converter using four 8:1 multiplexer. Take MSB ‘A’ as map-entered variable(input variable) ‘BCD’ lines as select lines, assuming f(A,B,C,D) as BCD input.

10. Realize a logic circuit for octal to the binary encoder.

11. Implement a full adder using a 3 to 8 decoder.

##### 12. Implement full adder using IC 74138.

13. Implement 3-bit binary to gray code conversion by using IC 74139.

14. Design a priority encoder for a system with a 3 inputs, the middle bit with the highest priority encoding to 10, the MSB with the next priority encoding to 11, while the LSB with least priority encoding to 01.

15. Design a 4 to 16 line decoder using 2 to 4 line decoder which has the active low outputs as active low enable input. Explain its operation.

16. Write the comparisons between PLA and PAL.

17. Design 7-segments decoder using PLA.

18. What is magnitude comparator? Design one-bit comparator and write the truth table, logic circuit using basic gates.

19. What is the parity generator? Explain with an example.

20. What is parity checker? Explain with example.

21. Obtain the characteristic equation of SR, JK, D and T flip-flops.

22. Explain the operation of edge triggered ‘D’ flip-flop with the help of a logic diagram and truth table. Also, draw the relevant waveforms.

23. Explain the working of pulse triggered JK flip-flop with typical JK flip-flop waveform.

24. Explain the working of Master-Slave JK flip-flops with a logic diagram.

25. What is contact bounce? With neat diagram, explain the working principles of Switch Debounce circuit.