Important RGPV Question

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CS-304 Digital Systems

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III Sem, CSE

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UNIT-1 Review of Number System and Number Base Conversions

UNIT-2 Combinational Logic-Half Adder, Half subtractor, full adder, full subtractor

UNIT-3 Sequential Logic-Flip-Flops, D, T, S-R, J-K Master-Slave, Racing Condition, Edge & Level Triggered Circuits

UNIT-4 Introduction to A/D & D/A Converters & their Types ,Sample and hold circuits, Voltage to frequency & frequency to voltage Conversion.

UNIT-5 Introduction to digital communication, Nyquist sampling theorem, Time Division Multiplexing

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UNIT 1

REVIEW OF NUMBER SYSTEMS

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AND

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NUMBER BASE CONVERSIONS

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Q.1) Given the following Boolean function: F(W,X,Y,Z) = WX'(Y’ + Z’) + X’.Z’.(W’ Y) where represents the XNOR operation, determine the simplified (minimal) SOP expression for F using boolean algebra and Implement the given function using NOR-NOR logic.

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(RGPV Nov 2022)

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Q.2) Draw a schematic for a minimal circuit that uses only NOR gates that performs the two’s complement operation on a four bit input value. Let the input be A3:0 and the output be B3:0.

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(RGPV Nov 2022)

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Q.3) Simplify the Boolean function F together with the don’t-care conditions d in following forms:

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i) sum-of-products

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ii) product-of-sums

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F(w, x, y, z)= Σ (0, 1, 2, 3, 7, 8, 10)

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d(w, x, y, z) = Σ (5, 6, 11, 15)

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(RGPV Dec 2020)

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Q.4) Give a Boolean expression that corresponds to this logic circuit. Develop a truth table for the circuit, showing columns for atleast the output of each 2-input gate. You should invent new variable names for these intermediate outputs.

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(RGPV Dec 2020)

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Q.5) Differentiate between analog and digital circuits.

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(RGPV Nov 2018)

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Q.6) Convert the following- (i) (48.625)10 =(); (ii) Divide (IEC87)16 by (A5)16 .

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(RGPV June 2014)

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Q.7) Convert the Following- (1) Decimal 225.225 to binary, octal and hexadecimal.

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(ii) Binary 11010111.110 to decimal, octal and hexadecimal.

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(RGPV June 2017)

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Q.8) Convert (412)10 to (i) Binary (ii)Octal

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(iii) Hexadecimal.

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(RGPV Dec 2017)

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Q.9) Convert the number (210.25)10 to base 2, 8.

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(RGPV June 2015)

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Q.10) Convert (41.6875)10 to (i) Binary (ii) Octal (iii) Hexadecimal.

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(RGPV May 2018)

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Q.11) Convert the following –

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(i) (1111)2= ( )10

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(ii) (10010.1011)2= ( )10

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(iii) (23)10 = ( )2

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(iv) (5.5)10 =( )2

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(v) (47.6)10 = ( )2

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(RGPV Nov 2018)

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Q.12) Do as directed-

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(i) (56)16 = (?)10

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(ii) (32)10 = (?)2

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(iii) Bubbled OR gate is also called………

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(RGPV Dec 2016)

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Q.13) Justify the following statements with examples – (i) Excess-3 code is self complementary code.

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(ii) Gray code is a reflected code.

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(RGPV May 2018)

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Q.14) Write briefly about error detecting and error correcting codes.

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(RGPV Dec 2014)

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Q.15) Define NAND and NOR gates and give their truth tables. Write down the boolean expressions for the output of each gate.

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(RGPV Nov 2018)

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Q.16) What do you understand by universal gate? Design all logic gates using universal gates.

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(RGPV June 2009)

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Or

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What is universal gate?

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(RGPV June 2014)

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Or

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What are universal gates? Explain with example.

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(RGPV Dec 2014)

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Or

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What are universal gates? Why are they called so?

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(RGPV Dec 2015)

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Or

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Why NAND gate is known as universal gate?

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(RGPV Dec 2016)

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Or

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What is universal gate? Implement AND, OR and NOT gates using NAND gates and NOR gates.

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(RGPV Dec 2017)

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Q.17)Implement the function F = A(B+ CD) + BC’ using NOR gate.

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(RGPV June 2017)

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Q.18) State and prove basic laws of Boolean algebra.

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(RGPV Dec 2013)

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Q.19) Write five theorem of Boolean algebra and simplify F (A+B)’ (A+B).

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(RGPV May 2018)

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Q. 20) What is Boolean algebra write any three theorems of Boolean algebra?

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(RGPV Dec 2017)

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Q. 21) State the distributive property of Boolean algebra.

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(RGPV Dec 2016)

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Q. 22) Simplify the following Boolean function to minimum numbers of literals –

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(i) zx+zx’y (ii) xy+xy’ (iii) y(wz’+wz) + xy.

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(RGPV June 2017)

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Q. 23) Simplify the following Boolean function with K-map- F(w, x, y, z) = (0, 1, 2, 4, 5, 6, 8, 9, 12, 13, 14).

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(RGPV June 2010, 2011, 2014)

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Or

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Simplify the Boolean function using K-map- F(A, B, C, D) = E(0, 1, 2, 4, 5, 6, 8, 9, 12,13, 14)

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(RGPV Dec 2017)

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Q. 24) Simplify the Boolean function with don’t care conditions and implement it with NAND gates- F(w, x, y, z) = E (1, 3, 7, 11, 15) d (w, x, y, z) = (0, 2, 5)

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(RGPV May 2018)

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Q. 25) Simplify the Boolean function

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F-B’C’D’ + BCD’+ ABCD’ and the don’t care condition d=B’CD’+A’BC’D.

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(RGPV June 2017)

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Q. 26) Explain Hamming and block codes.

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(RGPV June 2011)

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UNIT 2

COMBINATIONAL LOGIC-HALF ADDER,

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HALF SUBTRACTOR, FULL ADDER, FULL SUBTRACTOR

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Q.1) What is decoder? Explain BCD to decimal decoder.

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(RGPV June 2020)

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Q.2) Design a combinational circuit to convert the binary input ABCD to gray code.

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(RGPV June 2020)

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Q.3) Design the binary to octal Decoder and explain its working using block diagram.

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(RGPV Dec 2020)

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Q.4) Design Half adder using NAND gates. Also Draw the diagram?

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(RGPV Dec 2020)

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Q.5) Draw the truth table and logic diagram of full adder.

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(RGPV Dec 2015)

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Or

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Design and draw a full adder circuits.

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(RGPV Dec 2017)

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Q.6) Implement a full adder circuit with a decoder and two OR gates.

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(RGPV June 2014)

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Or

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Implement a full adder circuit with a (3 to 8 lines) decoder and two OR gates.

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(RGPV Dec 2017)

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Q.7) Explain full adder and design a full adder circuit using 3 to 8 decoder and two OR gates.

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(RGPV Dec 2016)

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Q.8) Design a full subtractor circuit using decoder and OR gates.

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(RGPV Dec 2015)

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Q.9) Design a full subtractor using logic gates.

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(RGPV Dec 2014)

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Q.10) Explain half subtractor circuit.

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(RGPV Dec 2013)

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Q.11) Design a full adder using minimum logic gates and also discuss he working of parallel adder.

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(RGPV Dec 2012)

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Q.12) Draw the logic diagram of look-ahead carry generator and explain Fits working.

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(RGPV Dec 2008, 2015)

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Or

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Explain the operation of look-ahead carry generator.

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(RGPV June 2007, 2008, 2010)

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Or

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Discuss/Explain the working of look ahead carry generator.

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(RGPV Dec 2012, June 2015)

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Or

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What is look ahead carry generator? Explain with logic diagram.

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(RGPV June 2014)

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Or

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Design and explain the working of look ahead carry generator.

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(RGPV Dec 2014)

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Or

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Explain look ahead carry generator.

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(RGPV Dec 2016)

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Q.13) Explain/Design BCD adders.

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(RGPV June 2008, 2012, Dec 2013)

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Or

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Design and explain the working of 4-bit BCD adder.

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(RGPV Feb 2010)

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Or

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Design a BCD adder and also give the rules of BCD addition.

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(RGPV June 2010)

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Or

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Design a BCD adder using logic gates.

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(RGPV Dec 2012)

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Or

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Design and explain the working of BCD adder.

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(RGPV Dec 2014)

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Or

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Draw the logic diagram of BCD adder and explain its working.

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(RGPV June 2007, Dec 2015)

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Or

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Write short note on BCD adders.

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(RGPV Dec 2017)

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Q.14) Draw and explain a 4-bit magnitude comparator.

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(RGPV June 2014)

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Q.15) Implement the following Boolean function using 4:1 multiplexer using A and B variables to the selection lines –

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F(A, B, C) = Σm(1, 4, 5, 7).

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(RGPV Dec 2015)

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Q.16) Design a BCD to excess-3 code converter.

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(RGPV Dec 2015, May 2018)

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UNIT 3

SEQUENTIAL LOGIC-FLIP-FLOPS, D, T, S-R, J-K MASTER- SLAVE, RACING CONDITION, EDGE & LEVEL TRIGGERED CIRCUITS

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Q.1) What is a Shift Register? Draw and explain shift Left- Right shift register.

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(RGPV Dec 2020)

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Q.2) Explain the race condition in S-R flip flop. Also explain how it is removed in J-K flip flop.

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(RGPV Dec 2020)

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Q.3) How a multiplexer can be used as ROM? Explain in brief.

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(RGPV Dec 2020)

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Q.4) Design a sequential circuit using T flip-flop for the following state table.

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Assume any suitable assumptions for state assignment.

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(RGPV Nov 2022)

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Q.5) Design a synchronous counter to count in the random sequence 0, 2, 4, 5, 7.0, 2, 4, 5, 7… using D flip-flop.

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(RGPV Nov 2022)

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Q.6) Explain the concept of working and applications of following memories-

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i) ROM

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ii) PLA

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iii) DRAM

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iv) FLASHRAM

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(RGPV Nov 2022)

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Q.7) Given the network of Fig., determine the functions f2 and f3 if f1 = xz+x’z’ and the overall transmission function is to be

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f(w, x,y,z)= Σ (0,3,6,10,11,12)

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(RGPV Nov 2022)

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Q.8) Each of the following functions actually represents a set of four functions, corresponding to the possible assignments of the don’t-care terms.

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F1 (w,x,y,z)= Σ (1,3,5,6,9,10)+ (11,12)

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F2(w,x,y,z)= Σ (0,3,4,5,8,9)+ (6,7)

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i) Find f3-f1.f2. How many functions does f3 represent?

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ii) Find f4= f1 +f2. How many functions does f4 represent?

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(RGPV Nov 2022)

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Q.9) Explain synchronous and Asynchronous counter.

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(RGPV June 2020)

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Q.10) What is Flip-Flop? Explain Master Slave J-K flip-flop.

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(RGPV June 2020)

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Q.11) Differentiate static and dynamic RAM.

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(RGPV Nov 2019)

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Q.12) Write short note on flash RAM.

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(RGPV Nov 2018, May 2019)

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Q.13) What are sequential circuits? What is the main difference between the combinational circuits and sequential circuits?

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(RGPV Nov 2018)

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Q.14) What is a flip-flop? Explain the principle of operation of R-S flip-flop with truth table.

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(RGPV Nov 2018)

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Or

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What is a lip-flop? Explain with a suitable example.

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(RGPV Dec 2017)

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Q.15) What is a shift register? Explain.

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(RGPV June 2010, Dec 2017)

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Or

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Discuss the shift registers.

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(RGPV June 2011)

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Q.16) Design a synchronous BCD counter with JK flip-flops.

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(RGPV Dec 2016)

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Q.17) Design a MOD-6 counter using J-K flip flops.

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(RGPV Dec 2012)

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Q.18) Design a MOD-12 binary counter using J-K flip-flop.

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(RGPV June 2015)

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Q.19) Find the MOD number of counter in fig Determine its counting sequence. Draw the state diagram. Find the frequency at output QD if input frequency is 7 kHz.

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(RGPV June 2014)

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Q.20) Give a brief introduction of a semiconductor memories.

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(RGPV Dec 2011)

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Or

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Give a comparison of various semiconductor memories.

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(RGPV June 2014)

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Q.21) State and differentiate between ROM, PROM. EPROM and EEPROM.

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(RGPV Dec 2014)

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Q.22) Write a short note on PLA.

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(RGPV Dec 2010, June 2012, May 2018, 2019)

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Or

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Explain PLAS.

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(RGPV Dec 2013)

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Q.23) What is RAM? Distinguish between SRAM and DRAM. What is PLA?

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(RGPV Dec 2015)

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Q.24) Design a combinational circuit using ROM. The circuit accepts a 3-bit number and generates an output binary number equal to the square of the input number.

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(RGPV June 2014)

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Or

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Derive a PLA program table for a combinational circuit that squares a 3-bit number.

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(RGPV June 2017)

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Q.25) A combinational logic circuit is defined by the functions – F1= Σ(3 , 5, 6, 7) and F₂ = Σ(0, 2, 4, 7). Implement the circuit with a PLA having three inputs, four product terms and two outputs.

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(RGPV Dec 2016)

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UNIT 4

INTRODUCTION TO A/D & D/A CONVERTERS & THEIR TYPES, SAMPLE AND HOLD CIRCUITS, VOLTAGE TO FREQUENCY & FREQUENCY TO VOLTAGE CONVERSION

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Q.1) Write notes on the following

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i) A/D and D/A convertors

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ii) CMOS Logic.

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(RGPV Nov 2022)

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Q.2) How is interfacing of TTL to MOS achieved?

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(RGPV Dec 2020)

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Q.3) Describe the application of Monostable multivibrator?

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(RGPV Dec 2020)

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Q.4) Implement the following circuit using CMOS logic

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i) Y=A.B

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ii) Y=A+B

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(RGPV June 2020)

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Q.5) With a neat diagram, explain the operation of 8 bit successive approximation ADC.

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(RGPV June 2020)

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Q.6) Drew and explain the working of A/D converter.

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(RGPV Nov 2019)

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Or

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With the help of circuit diagram explain the A to D converter.

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(RGPV June 2010, 2012)

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Or

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Explain A/D converter and its working.

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(RGPV Dec 2013)

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Or

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Explain analog to digital converter.

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(RGPV Dec 2016)

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Q.7) What is the need for A/D converter?

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(RGPV Dec 2014)

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Or

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What is the need of analog to digital conversion?

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(RGPV Dec 2015)

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Q.8) What are the applications of analog to digital converter?

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(RGPV June 2015)

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Q.9) Explain flash A/D converter with circuit diagram and parameters.

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(RGPV June 2011)

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Q.10) Discuss 3-bit analog to digital flash type converter.

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(RGPV May 2019)

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Q.11) Explain with the help of block diagram any one type of analog to digital converter.

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(RGPV Dec 2012)

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Or

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With a neat diagram explain successive approximation type A/D converter in detail.

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(RGPV Dec. 2010, 2014)

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Or

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Explain successive approximation techniques for analog to digital conversion.

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(RGPV Feb 2010, June 2015)

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Or

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Explain any one type of analog to digital converter in detail.

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(RGPV May 2018)

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Q.12) Why analog to digital converters is needed? Explain any one digital converters.

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(RGPV Dec 2017)

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Q.13) Enlist the various types of analog to digital (A/D) converter and explain any one of them with neat sketch.

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(RGPV Dec 2015)

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Q.14) State maximum conversion time and average conversion time.

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(RGPV Dec 2013)

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Q.15) Distinguish single slope and double slope A/D converter.

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(RGPV Dec 2014)

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Q.16) What is a bipolar D/A converter?

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(RGPV June 2014)

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Q.17) Explain a 4 bit R-2R ladder type D/A converter in detail.

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(RGPV Dec 2008, 2014)

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Or

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Explain the operation of R-2R ladder type digital to analog (D/A) converter with a neat sketch.

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(RGPV Dec 2015)

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Q.18) How can we describe the resolution of a digital to analog converter?

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(RGPV June 2015)

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Q.19) Explain the transfer characteristics and various performance parameters of DAC.

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(RGPV June 2015)

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Q.20) Discuss about the sample and hold circuits.

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(RGPV June 2009, Nov 2018)

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Or

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Write short note on sample and hold circuits.

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(RGPV Dec 2010, 2016, June 2017)

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Or

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Discuss about sample and hold circuits in A/D converter.

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(RGPV June 2011)

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Or

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Explain the principle working of sample and hold circuits.

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(RGPV Dec 2012)

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Or

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Draw the circuit diagram of sample and hold circuit and explain its working.

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(RGPV Dec 2015)

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Or

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Explain sample and hold circuit.

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(RGPV May 2019)

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Q.21) With the help of circuit diagram explain the V-F converter.

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(RGPV June 2012)

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Or

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Explain the principle working of V-F converter.

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(RGPV Dec 2012)

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Or

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With the help of circuit diagram explain the working of V-F converters.

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(RGPV Dec 2014)

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Or

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Explain voltage to frequency converter with the help of block diagram and waveforms.

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(RGPV Dec 2015, June 2017, May 2018)

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Or

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Write a short note on V-F converters.

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(RGPV June 2015)

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Q.22) Fig shows a computer control of motor speed. It can change motor speed from 0 to 1500 r.p.m. Find the number of bits of the computer so that it can control the speed within 1 r.p.m. of required speed.

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(RGPV June 2014)

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Q.23) Draw and explain the working of bistable multivibrator.

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(RGPV Dec 2005, June 2009, Nov 2019) 

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Or

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Describe bistable multivibrator with diagram and working principle.

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(RGPV June 2011)

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Q.24) Explain the terms-monostable, bistable and astable multivibrator.

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(RGPV Dec 2015)

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Q.25) Explain monostable multivibrator and write its applications.

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(RGPV June 2010, Dec 2010, 2017)

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Or

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With the help of timing diagram explain the working of monostable multivibrator.

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(RGPV June 2012)

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Or

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With the help of circuit diagram and timing waveforms explain the working of monostable multivibrator.

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(RGPV Dec 2014)

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Or

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Explain the operation of monostable multivibrator with the help of waveforms.

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(RGPV June 2015)

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Or

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Draw and explain the working of monostable multivibrator.

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(RGPV May 2018)

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Or

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Draw and explain monostable multivibrator.

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(RGPV May 2019)

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Q.26) Distinguish between monostable and astable multivibrator.

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(RGPV June 2017)

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Q.27) Draw and explain the working of Schmitt trigger.

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(RGPV Nov 2019)

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Or

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Discuss Schmitt trigger circuits.

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(RGPV June 2009, Dec 2013)

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Or

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Write short note on Schmitt trigger

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(RGPV June 2010, 2012)

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Or

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Draw a Schmitt trigger circuit and explain with waveforms.

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(RGPV, Nov./Dec. 2007, June 2015)

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Or

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With the help of circuit diagram explain the working of Schmitt trigger.

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(RGPV Dec 2012, 2014)

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Or

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Draw the circuit diagram of Schmitt trigger and explain its working.

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(RGPV Dec 2015)

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Or

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What is Schmitt trigger circuit?

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(RGPV June 2014)

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Or

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Write short note on Schmitt trigger circuits.

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(RGPV Dec 2017)

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Q.28) What do you understand by logic families?

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(RGPV June 2015)

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Q.29) Write characteristics of digital logic families.

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(RGPV Dec 2015)

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Q.30) Draw and explain DTL circuit. Enlist its advantages and disadvantages.

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(RGPV June 2017)

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UNIT 5

INTRODUCTION TO DIGITAL COMMUNICATION,

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NYQUIST SAMPLING THEOREM,

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TIME DIVISION MULTIPLEXING

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Q.1) Write notes on the following

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i) A/D and D/A convertors

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ii) Shannon’s theorem for channel capacity

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iii) Nyquist sampling theorem.      

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(RGPV Nov 2022)

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Q.2) Describe 2-bit simultaneous A/D Converter.

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 (RGPV Dec 2020)

nn

Q.3) Explain the procedure of Pulse code modulation with neat diagram?                                  

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(RGPV Dec 2020)

nn

Q.4) What are the advantages of TDM over FDM? Define synchronous TDM?                          

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(RGPV Dec 2020)

nn

Q.5) Compare the BPSK and BFSK modulation schemes.

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 (RGPV Dec 2020)

nn

Q.6) Write short note on sampling theorem.

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(RGPV Dec 2008, Nov 2018)

nn

Q.7) Write short note on Nyquist sampling theorem. 

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(RGPV Nov 2019)

nn

Q.8) Explain time division multiplexing.

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(RGPV May 2019)

nn

Q.9) Draw block diagram of PCM system and explain it.

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(RGPV Nov 2019)

nn

Q.10) Write short note on quantization error.       

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(RGPV Nov 2018)

nn

Q.11) What is quantization error? Explain sampling theorem. 

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(RGPV May 2019)

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Q.12) Explain quantization error.            

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(RGPV June 2014)

nn

Q.13) Explain the terms sampling, quantization and quantization error.

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  (RGPV Nov 2019)

nn

Q.14) Write short note on BFSK modulation.

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(RGPV Nov 2018)

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Or

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Explain BFSK.     

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(RGPV  May 2019)

nn

Q.15) Explain Shannon’s theorem for channel capacity.

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(RGPV May 2019)

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Or

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Explain the information capacity theorem for channel coding.

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Or

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Write short note on Shannon’s theorem for channel capacity.

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(RGPV Nov 2018)

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— Best of Luck for Exam —

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