B.TECH - Semester 3 digital electronics Question Paper 2020 (feb)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- When is Boolean algebra called Switching algebra? Implement the switching function $Y=B \bar{C}+\bar{A} B+D$.
- What is a Multiplexer? Draw the logic diagram of an $8: 1$ line multiplexer.
- What is ROM? Draw the basic structure of a ROM.
- Simplify the function $\mathrm{F}(\mathrm{A}, \mathrm{B}, \mathrm{C})=\sum(01367)+\sum d(245)$ where " d " denotes don't care.
- Show that a positive logic AND gate is negative logic OR.
- Draw a master slave JK flip flop and sketch its clock waveform.
- Compare Synchronous counter with Asynchronous counters.
- In what way Moore model differs from that of a Melay model.
- What are the steps for the design of asynchronous sequential circuit.
- What are hazards? Briefly explain the types of hazards. ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{4} \boldsymbol{=} \mathbf{4 0}$ Marks) Answer any two questions from each Module.Each question carries 10 marks.
- Simplify the given Boolean function. $$ F(A, B, C, D)=\sum m(0,1,3,4,6,7,12,15)+\sum d(13,14) . $$
- Implement a full subtractor using Demultiplexer. 10
- What is VHDL? Write the VHDL source code for a Full Adder.10
- Draw the TTL based NAND and NOR gates and explain their operation.10
- Design a four bit Johnson counter and obtain its timing diagram to illustrate the clock input and all flip flop outputs.
- Draw the logic diagram of a 4 bit serial input/serial output shift register. Indicate the inputs, outputs and a negative edge triggered clock in its timing diagram.
- With suitable block diagram explain Moore circuit and Melay circuit models.
- An asynchronous sequential circuit is described by the following excitation (Y) and output function (Z). $$ \begin{aligned} & Y=X_{1} X_{2}+\left(X_{1}+X_{2}\right) Y \\ & Z=Y . \end{aligned} $$ (i) Draw the logic diagram of the circuit. (ii) Derive...
- For the given Boolean function ' $F$ ' obtain the hazard free circuit. $$ \mathrm{F}(\mathrm{~A}, \mathrm{~B}, \mathrm{C}, \mathrm{D})=\sum m\left(\begin{array}{l} 1 \\ 3 \\ 6 \end{array} 71315\right) $$