# Digital Logic - Unit Wise Questions

1. What are the various types of numbering system use in the digital logic? Explain. Convert the 3EC8_{16} into different numbering system that you know.

4. Convert the following decimal numbers to the indicated bases.

(a) 7562.45 to octal

(b) 1938.257 to hexadecimal

(c) 175.175 to binary

4. Perform the arithmetic operation (+42)+(-13) and (-42)-(-13) in binary using the signed -2's-complement representation for negative numbers.

4. Convert the following hexadecimal number to decimal and octal numbers

(a) _{0}FFF (b) _{3}FFF

4. Convert the following hexadecimal number to decimal and octal numbers.

a) 4FF

b) 6FED

4. Convert the hexadecimal number 2BFC to binary and then to octal.

4. What do you mean by the Gray code? What are its application?

4. Differentiate between Analog and Digital system.

5. Explain the error detection code with example.

5. Convert the following decimal numbers into hexadecimal and octal number.

(a) 304 (b) 224

5. Covert the following:

a) A08E. FA_{16} = (? )_{10}

b) AE9. BOE_{16} = (? )_{2}

5. Convert the following decimal number into hexadecimal and octal.

a. 334

b. 225

5. Convert the following decimal numbers into Hexadecimal and Octal numbers:

(a) 504

(b) 250

5. Convert the following decimal numbers into hexadecimal and octal number.

(a) 220

(b) 1020

5. Convert the following octal numbers to hexadecimal.

a. 1760.46

b. 6055.263

10. Explain the Ripple Counter.

5. Express the Boolean Function F = A + B' C in a sum of minterms .

5. Proof the De-Morgan 1st and 2nd theorem with truth table and logic gates.

6. Explain the duality theorem with example.

6. State and prove commutative laws, associative laws and distributive law using logic gate and truth table.

6. Proof the 1^{st} and 2^{nd} law of De Morgan’s theorems with logic gate and truth table.

6. Which gates can be used as inverts in additional to the NOT gate and how?

7. What do you mean by Universal gate? Realize the following logic gates using NOR gates.

(a) OR gate (b) AND gate

7. Show that both NAND gate and NOR gate are universal gates.

7. Draw a logic gates that implements the following

8. State and prove De-Morgan’s theorem 1st and 2nd with logic gates and truth table.

8. Prove that:

12. Write short notes on (**any two**):

(a) State diagram

(b) De-Morgan's theorem

(c) TTL

13. Write short notes on:-

a) CMOS

b) Universal gates

c) Error detection code

5. Express the complement of the following function in sum of minterms.

6. Reduce the following function using k-map

F = wxy + yz + xy'z + x'y

6. Reduce the following function using k-map

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

6. Simplify, the following Boolean function using three variable K-map.

a) F(X,Y,Z) = ∑(0,3,2,5)

b) F(A,B,C) = ∑(0,2,4,5,6)

6. Describe the three Variable K-map with example.

6. Explain the K-map with three variables.

7. Simplify the Boolean expression.

prepare truth table to show that the simplified expression is correct or not?

8. Write a procedure to reduce K-maps.

9. Reduce the following expressions using K-map

9. Reduce the following expression using K-map.

9. Simplify the Boolean function using K-Maps.

F = X’yz + X’yz’ +Xy’z’ +Xy’z

2. What do you mean by full adder and full subtractor? Design a 3 to 8 line decoder using two 2 to 4 line decoder and explain it.

2. Design a full subtractor with truth table and logic gates.

3. Design the full subtractor circuit with using Decoder and explain the working principle.

3. Explain the full subtractor with using decoder.

4. Design a half subtractor circuit using only NAND gates.

4. Design a half adder logic using only NOR gate.

4. Design a half adder logic using only NAND gates.

4. Design a half subtractor using only NOR gates.

5. Design a half adder logic circuit using NOR gates only.

7. Design half adder logic circuit using only universal gates.

7. Explain the combination logic with examples.

8. What is combinational logic? What are its important features.

11. Differentiate between combinational logic and sequential logic. List some applications of sequential logic.

1. Implement the following function using

(a) Decoder

(b) Multiplexer

(c) PLA

1. Implement the following function using

(a) Decoder

(b) Multiplexer

(c) PLA

1. What is the magnitude comparator? Design a logic circuit for 4 bit magnitude comparator and explain it.

1. Draw a block diagram, truth table and logic circuit of 1x16 Demultiplexer and explain its working principle.

1. What is decoder? Implement the following using decoder.

(a) F (W X Y Z) = Σ (0,1,3,4,8,9,10)

(b) F (W X Y Z) = Σ (1,3,5,6,11,13,14)

1. Explain the magnitude comparator and also design a logic diagram for 4 bit magnitude comparator.

1. Design Magnitude comparator and also design a logic diagram for a 4 bit magnitude comparator.

1. Draw a block diagram, truth table and logic circuit of a 16 x 1 multiplexer and explain its working principle.

2. Differentiate between PAL and PLA. Design a counter as shown in the state diagram below

2. What do you mean by decoder? Design a 3 to 8 line decoder using 2 to 4 line decoder and explain it.

2. Design a magnitude comparator using logic gates and truth table.

3. Draw a block diagram, truth table and logic circuit of 1*16 Demultiplexer and explain its working principle.

3. The following is a truth table of a 3-input,4 output combinational circuit. Tabulate the PAL programming table for the circuit and mark for the circuit and mark the fuses to be blown in a PAL diagram.

3. What is magnitude comparator? Design a logic circuit for _{4} bit comparator and explain it.

3. What is demultiplexer? Draw its block diagram and explain its working principle.

3. Design a decimal adder with logical diagram and truth table.

7. Design a combinational circuit with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is one less than the input.

7. Design a combinational circuit with three inputs and six outputs. The output binary number should be the square of the input binary number.

6. Design an encoder using universal gates.

6. Design a multiplexer 4x1 using only universal gates.

8. Implement half adder using 2-4 decoder.

9. Design the priority encoder circuit.

9. Design and explain the Decimal adder with truth table and suitable diagram.

7. Design the Decoder using Universal gates.

8. Draw a logic circuit of 4 x 1 multiplexer.

8. Draw a logic circuit of 8*1 multiplexer.

8. Explain the PLA (Programmable Logic Array).

8. Differentiate between Multiplexer and demultiplexer.

9. Design the 4 bit parallel binary adder.

10.Differentiate between a MUX and a DEMUX.

10. Explain the PLA with the block diagram.

11. Explain the decoder and design with universal gates.

11. Explain the operation of Decoder.

11. Draw a 3 to 8 decoder circuit and explain its operation.

11. Design the decimal adder.

12. Design a 4 input multiplexer using logic diagram and truth table.

12. Explain the decimal adder.

12. Explain the programmable logic array.

13. Write short notes on **(any two):**

a. Decoder b. Integrated circuit c. PLA.

13. Write short notes on :

(a) Programmable Logic Array

(b) Triggering at flip-flop

(c) Memory Unit

1. Design and implement with logic diagram of synchronous 3 bit up down counter using J-K flip flop.

1. Design the 4-bit synchronous up/down counter with timing diagram, logic diagram and truth table.

2. Design clocked sequential circuit of the following state diagram by using JK flip-flop.

3. What is JK master slave flip-flop? Design its logic circuit, truth table and explain the working principle.

3. Explain the Master-slave S-R flip-flop with logic diagram, truth table and timing diagram.

3. Design a master-slave S-R flip flop with logic diagram and truth table.

8. Design a 5 x 32 decoder with four 3 x 8 decoder with enable and one 2 x 4 decoder. Use block diagrams only.

7. What is J-K flip flop? Explain.

7. What do you mean by D-flip-flop?

8. What is sequential logic? What are the important features?

11. Explain master slave J-K flipflop.

9. How JK flip flop can convert into a D-flip flop?

9. Describe the clocked RS flip-flop.

9. What is flip-flop? Mention the application of flip-flop.

10. How does a J-K flip flop differs from an S-R flip flop in its basic operations? Explain.

10. What do you mean by triggering of flip flop?

11. Explain the R-S flip flop with truth table.

12. What do you mean by clocked RS flip-flop ?Explain

13. What do you mean by Synchronous counter?

13. Write short note on (any two):

a) Flip flop

b) Synchronous Counter

c) Digital systems.

13. Write short notes on :

(a) Asynchronous counter

(b) Multiplexers

(c) State reduction table

2. Design a 3 bit synchronous counter and explain it.

2. What do you mean by asynchronous counter? Design a mod-6 synchronous counter using T flip-

flops.

2. What do you mean by ripple counters? Explain with timing diagram.

2. Design the mod-6 asynchronous counter and explain with truth table.

2. Explain the 4 bit ripple counter and also draw a timing diagram.

3. What do you mean by ripple counter? Explain the design procedure of sequential circuits.

10. What is the difference between a serial and parallel transfer? Explain how to convert serial data to parallel and parallel data to serial. What type of register is needed?

10. Explain shift register with parallel load. Highlight on its practical implications.

9. What are the various types of shift registers?

9. Mention the difference types of shift register.

11. Design a 4-bit binary ripple counter with D flip-flops.

12. Write short notes on (**any two**):

(a) SIMM

(b) RTL

(c) Parity Checker

10. Draw a parallel-parallel-out shift register and explain it.

10. Draw a logic diagram of a 4 bit ripple counter using D-flip flop.

10. What do you mean by synchronous counter? Explain with truth table.

10.What do you mean by Ripple counters?

11. What are the shift Register operations?

11. Differentiate between a counter a shift register.

11. Explain the 4 bit ripple counter.

12. Describe the Ripple counter.

12. Mention the difference types of shift register and explain.

12. What are the various types of shift registers?

12. What do you mean by shift registers? Explain.

12. Explain the shift register with example.

13. Write short notes on:

(a) Registers. (b) Digital. (c) EBCDIC.

13. Explain the serial-In, parallel out shift register.

13. Write short note on (any two):

a) Binary counter

b) State reduction

c) Negative edge triggering