22320

11819
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.

Marks

1. Attempt any FIVE of the following: 10

a) Write the radix of binary, octal, decimal and hexadecimal
number system.
b) Draw the circuit diagram for AND and OR gates using diodes.
c) Write simple examples of boolean expression for SOP and POS.
d) State the necessity of multiplexer.
e) Draw logic diagram of T flip-flop and give its truth table.
f) Define modulus of a counter. Write the numbers of flip flops
required for Mod-6 counter.
g) State function of preset and clear in flip flop.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Draw the block diagram of Programmable Logic Array.
b) Convert -
(i) (255)10 = ( ? )16 = ( ? )8
(ii) (157)10 = ( ? )BCD = (? ) Excess3
c) Draw the symbol, truth table and logic expression of any
one universal logic gate. Write reason why it is called
universal gate.
d) Minimize the following expression using K-Map.
f (A, B, C, D) = Σm (0, 1, 2, 4, 5, 7, 8, 9, 10)

3. Attempt any THREE of the following: 12

a) Compare TTL and CMOS logic families on the basis of
following:
(i) Propagation delay
(ii) Power Dissipation
(iii) Fan-out
(iv) Basic gate
b) Describe the function of Full Adder Circuit using its truth table,
K-Map simplification and logic diagram.
c) Realize the basic logic gates, NOT, OR and AND gates using
NOR gates only.
d) Describe the working of JK flip-flop with its truth table and
logic diagram.

4. Attempt any THREE of the following: 12

a) Draw and explain working of 4 bit serial Input parallel Output
shift register.
b) Draw 16:1 MUX tree using 4:1 MUX.
c) Calculate analog output of 4 bit DAC for digital input 1101.
Assume VFS = 5V.
d) State De Morgan’s theorem and prove any one.
e) Design one digit BCD Adder using IC 7483.
22320 [3]
Marks
5. Attempt any TWO of the following: 12
a) Subtract using 2’s compliment method
(35)10 – (5)10
b) Design a 4 bit synchronous counter and draw its logic diagram.
c) Describe the working of successive Approximation ADC. Define
Resolution and conversion time associated with ADC.

6. Attempt any TWO of the following: 12

a) Design 4 bit Binary to Gray code converter.
b) Compare the following (Any three points)
(i) Volatile with Non-volatile memory
(ii) SRAM with DRAM memory
c) Give block schematic of decade counter IC 7490. Design
Mod-7 counter using this IC.
 22320
21819
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(7) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.

Marks

1. Attempt any FIVE of the following: 10

a) List the binary, octal and hexadecimal numbers for decimal
no. 0 to 15.
b) Define fan-in and fan-out of a gate.
c) Compare between synchronous and asynchronous counter (any
two points).
d) State two specification of DAC.
e) Write the gray code to given no. (⊥⊥0⊥)2 = (?) Gray.
f) Define encoder, write the IC number of IC used as decimal to
BCD encoder.
g) Draw the logical symbol of EX-OR and EX-NOR gate.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Convert:
(i) (AD92 . BC A)16 = (?)10 = (?)8 = (?)2
b) Simplify the following and realize it
Y = A + A BC + A B C + ABC + A B
c) Explain the flowing characteristics w.r.t logic families:
(i) Noise margin
(ii) Power dissipation
(iii) Figure of merit
(iv) Speed of operation
d) Draw logic diagram of half adder circuit.

3. Attempt any THREE of the following: 12

a) Draw the circuit of successive approximation type ADC and
explain it’s working.
b) Describe the operation of R-5 flip-flop using NAND gates only.
c) Give classification of memory and compare RAM and ROM
(any four points).
d) State the applications of shift register.

4. Attempt any THREE of the following: 12

a) Subtract the given number using 2’s complement method:
(i) (⊥⊥0⊥⊥)2 – (⊥⊥⊥00)2
(ii) (⊥0⊥0)2 – (⊥0⊥)2
b) State De-Morgan’s theorem and prove any one.
c) Compare between PLA and PAL.
d) Reduce the following expression using K-map and implement it
F (A, B, C, D) = p M (1,3,5,7,8,10,14)
e) Describe the working of J-K flip- flop and state the race
around condition.
22320 [3]
Marks
5. Attempt any TWO of the following: 12
a) Design BCD to seven segment decoder using IC 7447 with its
truth table.
b) Describe the working of 4 bit universal shift register.
c) Design basic logic gates using NAND and NOR gate.

6. Attempt any TWO of the following: 12

a) Design a mod-6 Asynchronous counter with truth-table and
logic.
b) Design ⊥:8 demultiplexer using 1:4 demultiplexer.
c) Draw the circuit diagram of 4 bit R-2R ladder DAC and
obtain its output voltage expression.
 22320
11920
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.

Marks

1. Attempt any FIVE of the following: 10

a) Convert (D8F)16 into binary and octal.
b) Draw Symbol, Truth Table and logic equation of Ex-OR gate.
c) State the DeMorgan's Theorems.
d) Convert the following expression into standard SOP form.
Y = AB + AC + BC
e) Draw symbol and write truth table of D and T Flip Flop.
f) Write down number of flip flops are required to count 16
clock pulses.
g) List the types of DAC

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Perform the subtraction using 2'S Complement methods.
(52)10 – (65)10
b) Simplify the following Boolean Expression and Implement using
logic gate.
ABC D + ABCD + ABCD + ABCD
c) Minimize the four variable logic function using K map.
f(A,B,C,D) = ∑m(0, 1, 2, 3, 5, 7, 8, 9, 11, 14)
d) Implement the following functions using demultiplexer.
f1 = ∑m (0, 2, 4, 6)
f2 = ∑m (1, 3, 5)

3. Attempt any THREE of the following: 12

a) Realize the following logic expressions using only NAND gates.
(i) OR
(ii) AND
(iii) NOT
b) Draw binary to gray converter and write its truth table.
c) Describe the working of JK flip flop with truth table and
logic diagram.
d) Describe the working of 4 bit SISO (serial in serial out)
Shift Register with diagram and waveform if input is 01101.

4. Attempt any THREE of the following: 12

a) Design a full Adder using Truth Table and K-map.
b) Describe the working of ring counter using D flip flop with
diagram and waveforms.
c) Draw block diagram of programmable logic Array.
d) Compare the following:
(i) Volatile with Non Volatile.
(ii) EPROM with EEPROM.
e) Describe the working principle of successive approximation ADC.
22320 [3]
Marks
5. Attempt any TWO of the following: 12
a) (i) Convert the following binary number (11001101)2 into
Gray Code and Excess-3 Code.
(ii) Perform the BCD Addition.
(17)10 + (57)10

(iii) Perform the binary addition.

(10110 • 110)2 + (1001 • 10)2
b) Design a 4bit ripple counter using JK flip flop, with truth
table and waveforms.
c) Calculate the analog output for 4 bit weighted register type
DAC for inputs
(i) 1011
(ii) 1001
Assume (Vfs) full scale range of voltage is 5V

6. Attempt any TWO of the following: 12

a) Compare TTL, CMOS and ECL logic family on the following
points.
(i) Basic Gates
(ii) Propogation delay
(iii) Fan out
(iv) Power Dissipation
(v) Noise immunity
(vi) Speed Power Product.
b) Design a BCD adder using IC 7483.
c) Design a 3 bit synchronous counter using JK FlipFlop.
 22320
11920
3 Hours / 70 Marks
 22320
21222
3 Hours / 70 Marks Seat No.
15 minutes extra for each hour

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.

Marks

1. Attempt any five of the following: 10

a) Convert (1101011)2 = (    )16 and
(1111011)2 = (    )8
b) List triggering methods used for triggering flip flops.
c) Define Minterm and Maxterm w.r.t. K-map.
d) Define shift register and list its types.
e) List any two specifications of IC-DAC 0808.
f) Draw logical circuit diagram of half adder circuit.
g) Write truth table of D type flip-flop.

P.T.O.
22320 [2]
Marks
2. Attempt any three of the following: 12
a) Convert (43)10 = (BCD)
(34)10 = (Excess-3)
(110111)2 = (Gray)
(11101)2 = (2’s complement)
b) Draw logical diagram of full adder using K-map simplification
and write truth table.
c) Draw the block diagram of programmable logic Array with
proper labels.
d) Draw the circuit diagram of BCD to 7 - segment decoder
and write truth table.

3. Attempt any three of the following: 12

a) State and prove two De-Morgan’s Theorems.
b) Draw basic gates AND, OR and NOT using NAND gate only.
c) Draw 4 bit ring counter with truth table and its waveform.
d) Compare the following: (Any two points each)
(i) Volatile - Non volatile memory
(ii) SRAM - DRAM memory

4. Attempt any three of the following: 12

a) Realize given boolean expression using basic gates and
simplify same.
y = AB + BC (B + C)
b) Design 4 bit binary to gray code converter. Using truth table.
c) Realize given expression using K-map
f (A, B, C, D = Σ m (3, 5, 7, 8, 10, 11, 12, 13)
d) Draw JK master slave flip flop and explain its operations.
e) Calculate analog o/p of 4 bit DAC for digital input is 1100.
Assume VFS = 5 V
22320 [3]
Marks
5. Attempt any two of the following: 12
a) Draw and explain operation 4 bit universal shift register.
Draw necessary waveforms.
b) Draw block diagram of Dual slope ADC and explain its
working.
c) Subtract following using Two’s complement method.
(15)10 – (32)10

6. Attempt any two of the following: 12

a) Design MOD-12 ripple counter. Write its truth table with
waveform.
b) Design 16:1 MUX using 4:1 MUX.
c) Compare TTL and CMOS with following points.
(i) Fan IN
(ii) FAN OUT
(iii) Propogation delay
(iv) Power dissipation
 22320
12223
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(7) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.

Marks

1. Attempt any FIVE of the following : 10

a) Write radix of binary, octal, hexadecimal number system.
b) State necessity of demultiplexer.
c) Draw symbol and write the truthtable for T - flipflop.
d) Compare between synchronous and asynchronous counter.
e) Write gray code to given number (11111)2 = (?)Gray
f) State two features of ADC IC0809.
g) Draw four variable K-map.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following : 12
a) Sketch the given Boolean expression; use one AND gate one
OR gate only Y = AB + AC.
b) Draw circuit diagram of BCD to seven segment decoder and
write its truth table.
c) Draw the block diagram of programmable array logic.
d) Minimize following expression using K-map.
f(A,B,C,D) = Σm  (1,5,6,7,11,12,13,15)

3. Attempt any THREE of the following : 12

a) Realize the following logic operation using only NOR gates :
AND, OR, NOT.
b) Describe the operation of 4 bit serial in serial out shift register.
c) Calculate the analog output of 4 bit DAC if the digital
input is 1101. Assume VFS = 5 V
d) Describe the working of SR flipflop with its truth table and
logic diagram.

4. Attempt any THREE of the following : 12

a) Draw symbol, truth table and logical output equation of OR
and EX-OR gate.
b) Describe function of full adder circuit with its truth table
and logical diagram.
c) Design 16:1 multiplexer using 4:1 multiplexer.
d) Describe working of Master-slave JK flipflop with truth table
and logic diagram.
e) Compare between R-2R ladder DAC and weighted resistor
DAC (Four points).
22320 [3]
Marks
5. Attempt any TWO of the following : 12
a) Explain 3 bit asynchronous counter with output waveforms.
b) Compare following (Any three points)
i) RAM with ROM memory.
ii) EPROM with EEPROM memory.
c) Convert the following.
i) (6AC)16 = (?)10
ii) (2003)10 = (?)16
iii) (228)10 = (?)BCD

6. Attempt any TWO of the following : 12

a) Give the block schematic of decade counter IC 7490. Design
mod-7 counter using IC.
b) Design a four bit BCD adder using IC-7483 and NAND
gate only.
c) Draw the circuit and explain the principle of TTL gate
with totempole output
 22320
22223
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(7) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
(8) Preferably, write the answers in sequential order.
Marks

1. Attempt any FIVE of the following: 10

a) State the base of following number system:
Decimal, binary, octal, hexadecimal
b) Define counter.
c) Give any two applications of comparator.
d) Draw the symbol of D flipflop and write its truth table.
e) Name the types of RAM.
f) Define and draw logic symbol of demultiplexer.
g) List the basic types of shift register.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Convert the given binary into decimal, octal, hexadecimal
and gray code:
(10110101)2
b) Draw the block diagram of BCD to 7 segment decoder using
IC 7447. Write truth table of it.
c) Define PLA. Draw its block diagram.
d) Implement full adder using two half adder.

3. Attempt any THREE of the following: 12

a) Draw the OR gate and NOR gate using NAND gate only.
b) Compare TTL, ECL and CMOS logic families. (any four points)
c) Draw 4 bit twisted ring counter and explain working with truth
table and waveforms.
d) A combinational circuit is defined as F1 = ∑m (3, 5, 7) and
F2 = ∑m (4, 5, 7). Implement the circuit with a PLA having
3 inputs, 3 product terms and 2 outputs.

4. Attempt any THREE of the following: 12

a) Define following terms :
i) Fan-in
ii) Fan-out
iii) Power dissipation
iv) Noise margin
b) Draw the block diagram of digital comparator IC 7485 and
explain with the help of truth table.
c) Design 32 : 1 multiplexer using 8 : 1 multiplexer.
d) Explain the working of master salve JK flipflop with truth
table and logic diagram.
e) Write applications of ADC and DAC.
22320 [3]
Marks
5. Attempt any TWO of the following: 12
a) Design nod-6 counter using IC 7490 and explain its design
with working.
b) Explain classification of memories. What is flash memory?
c) i) State the rules of BCD addition. (2)
ii) Perform BCD addition of : (4)
(972)10 + (348)10

6. Attempt any TWO of the following: 12

a) Design synchronous decade counter using D’ flipflop.
b) i) Minimize the following expression using K-map. (4)
Y = ∑m (0, 2, 5, 7, 8, 10, 13, 15)
ii) Realize the minimized expression using basic gates. (2)
c) Reduce following boolean expressions using boolean laws.
i) Y = AB + AB + AB + A B (2)
ii) Y = ABC + ABC + ABC (2)
iii) Y = ABC + ABC + ABC (2)
 22320
23124
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
Marks

1. Attempt any FIVE of the following: 10

a) List the octal and hexadecimal numbers for decimal number
0 to 15.
b) Convert (159)10 = ( ? )8
Convert (380)10 = ( ? )16
c) Draw symbol, truth table of NAND gate.
d) Define min-term and max-term with respect to K-map.
e) List the types of DAC.
f) State two features of ADC IC0809.
g) List the types of semiconductor memories.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Perform the subtraction using 2’s complement methods.
(10110)2 – (11010)2
b) Explain the following characteristics with respect to logic
families -
i) Power dissipation
ii) Fan-in and fan-out
iii) Noise margin
iv) Speed of operation
c) Draw logic diagram of half adder using K-map simplification
and write truth table.
d) Describe the working of J-K flip-flop and state the race
around condition.
e) Give classification of memory and compare RAM and ROM.
(Any four points)

3. Attempt any FOUR of the following: 16

a) Convert (53)10 = (BCD)
(34)10 = (Excess-3)
(100111)2 = (Gray)
(11010)2 = (2’s complement)
b) State and explain De-Morgan’s theorems.
c) Draw 16 : 1 mux tree using 4 : 1 mux.
d) Describe the operation of R-S flip-flop using NAND gate.
e) Describe the operation of 4 bit serial in serial out shift
register.
f) Draw and explain the block diagram of Programmable Logic
Array (PLA).
22320 [3]
Marks
4. Attempt any TWO of the following: 16
a) Design 1 : 8 demultiplexer using 1 : 4 demultiplexer. Also write
truth table.
b) Explain the role of counters in digital circuits and design
Mod - > counter using IC 7490.
c) Draw and explain the block diagram of dual slope ADC. Also
write it’s specifications.

5. Attempt any TWO of the following: 16

a) Design basic logic gates using NAND and NOR gate.
b) Minimize the following expression using K-map.
f (A, B, C, D) = ∑ m (0, 1, 2, 4, 5, 7, 8, 9, 10)
Also explain SOP and POS form.
c) Draw and explain 4-bit universal shift register. Also explain
the necessity of register in digital circuits.
 22320
23242
3 Hours / 70 Marks Seat No.

Instructions – (1) All Questions are Compulsory.

(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
(7) Preferably, write the answers in sequential order.
Marks

1. Attempt any FIVE of the following: 10

a) List the uses of following codes:
i) BCD code
ii) ASCII
b) Write the one application of SR-FF and mention its one
drawback.
c) State the advantages of using tri state logic in combinational
logic.
d) Draw excitation table of T FF.
e) List any two specifications of IC 0809.
f) Define : Encoder
g) Name four types of shift register.

P.T.O.
22320 [2]
Marks
2. Attempt any THREE of the following: 12
a) Perform the following subtractions using 2'S compliment
method.
i) (1100) – (0011)
ii) (10101) – (11100)
b) Draw the MUX tree for 32 : 1 MUX using 4 : 1 MUX only.
c) Name the basic building block used in CPLD and state their
functions.
d) Minimize the following expression using K-map :
f (A, B, C, D) = Σ m (2, 3, 6, 10, 11, 12, 14, 15)

3. Attempt any THREE of the following: 12

a) Compare TTL and CMOS logic on the basis of :
i) Noise margin
ii) Figure of merit
iii) Speed of operation
iv) Fan in
b) Realize the following logic operations using only NOR gates
i) OR
ii) EX-NOR
c) Design the IC7490 as mod-B counter and describe its
operation.
d) Calculate the analog output of 8-Bit DAC for digital input
10011100. Assume V full scale = 5V.
22320 [3]
Marks
4. Attempt any THREE of the following: 12
a) Draw the symbol, truth table and logical expression of
following gates :
i) EX-OR gate
ii) NAND gate
b) Draw the full adder circuit's logic diagram, truth table and
K-map simplification.
c) Draw the binary to gray code converter with the help of
truth table and its K-map simplification.
d) Describe the working of clocked SR flip-flop with preset and
clear.
e) Describe the working principle of dual slope type of ADC
with neat diagram.

5. Attempt any TWO of the following: 12

a) Design 4-bit ripple counter and draw output waveforms.
b) Compare weighted resister DAC with R-2R ladder type DAC
(any six points).
c) Convert the following
i) (ABCD)16 = ( ? )10
ii) (101011001111)2 = ( ? )10
iii) (101011001111)2 = ( ? )8

6. Attempt any TWO of the following: 12

a) Draw universal shift register and describe its operation.
b) Draw the 4-Bit adder, circuit using IC7483 and describe its
working with suitable examples.
c) Draw the circuit diagram of 3-input TTL NAND gate and
explain its working.