Digital Techniques_Four Marks Questions

Question Bank

1) Define following terms related to logic families :

(i) Noise Margin

(ii) FAN-OUT

(iii) Propagation delay

(iv) Power dissipation

2) State Demorgan’s theorem’s and prove both theorems using truth table.

3) State functions of preset, clear, clock and SR inputs related to SR flip flop.

4) Sketch diagram of 4 bit asynchronous counter using suitable flip flop. Sketch timing diagram.

5) Perform binary subtraction using 2’s complement method (11001)2 – (1010)2.

6) State DeMorgan’s theorems and prove by Truth-table method for two variables.

7) Give the expression of Grey code equivalent of 4-bit binary using K-map.

8) Draw the circuit diagram of 3-bit asynchronous up/down counter using T-FF.

9) Describe any four specifications of DAC.

10) Perform the following: (11011)2 × (11011)2

11) State the rules for BCD Addition explain with example.

12) Design Half adder using K-map and implement using gates.

13) Subtract (1101)2 from (1110)2 using 1’s & 2’s complement method.

14) Design 1 : 32 De MUX using 1 : 8 De MUX.

15) Write down excitation table of JK & DFF.

16) Perform following binary operations :

(i) 1011        (ii) 1101

  × 101               – 110       (using 2’s complement method)

17) Design full adder using K-map technique.

18) Draw the logical diagram of clocked S-R flip-flop using NAND gate only.Write its truth table.

19) With the help of circuit diagram, describe the operation of weighted resistor DAC.

20) Convert following numbers into binary and add them (173)8 + (741)8.

21) Why NAND gate is called universal gate ? Implement basic gates using NAND gate only.

22) Draw the block diagram of ALU IC 74181 and also write its operation.

23) Write the difference between combinational and sequential logic circuit. (any four points).

24) Design 4 bit asynchronous up-counter also write the truth table and draw the waveform.

25) Compare between R-2R ladder DAC and weighted resistor DAC (4 points).