ECE - III Yr - VI Sem - QB Formatted

RANGANATHAN ENGINEERING COLLEGE

Coimbatore- 641 109

Department of Electronics and Communication Engineering

III Year – VI Semester

Question Bank

SL.No Name Of the Subject Staff Name Page No

1 VLSI Design Mr. S.A.Siva kumar 01

2 Digital Communication Mr. Vignesh Chandrasekar 21

3 Antenna and Wave Propagation Mr. G.Arun Francis 40

4 Micro Controllers and RISC Architecture Mr. S. Ganesh prabhu 56

5 Digital Image Processing Mr.R. Senthil Ganesh 71

6 Medical Electronics Mrs. S. Kalyani 99

Student Name :

Register No :

VLSI DESIGN

VLSI DesignUNIT I

Part A -2 Mark Questions & Answers

1.What are four generations of Integration Circuits?

+ SSI (Small Scale Integration)

+ MSI (Medium Scale Integration)

+ LSI (Large Scale Integration)

+ VLSI (Very Large Scale Integration)

2.Give the advantages of IC?

+ Size is less

+ High Speed

+ Less Power Dissipation

3.Give the variety of Integrated Circuits?

+ More Specialized Circuits

+ Application Specific Integrated Circuits(ASICs)

+ Systems-On-Chips

4.Give the basic process for IC fabrication

+ Silicon wafer Preparation

+ Epitaxial Growth

+ Oxidation

+ Photolithography

+ Diffusion

+ Ion Implantation

+ Isolation technique

+ Metallization

+ Assembly processing & Packaging

5.What are the various Silicon wafer Preparation?

+ Crystal growth & doping

+ Ingot trimming & grinding

+ Ingot slicing

+ Wafer polishing & etching

+ Wafer cleaning.

6.Different types of oxidation? Dry & Wet Oxidation

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VLSI DESIGN

7.What is the transistors CMOS technology provides?

n-type transistors & p-type transistors.

8.What are the different layers in MOS transistors? Drain , Source & Gate

9.What is Enhancement mode transistor?

The device that is normally cut-off with zero gate bias.

10. What is Depletion mode Device?

The Device that conduct with zero gate bias.

11.When the channel is said to be pinched –off?

If a large Vds is applied this voltage with deplete the Inversion layer .This Voltage effectively pinches off the channel near the drain.

12.Give the different types of CMOS process?

+ p-well process

+ n-well process

+ Silicon-On-Insulator Process

+ Twin- tub Process

13.What are the steps involved in twin-tub process?

> Tub Formation

> Thin-oxide Construction

> Source & Drain Implantation

> Contact cut definition

> Metallization.

14.What are the advantages of Silicon-on-Insulator process?

> No Latch-up

> Due to absence of bulks transistor structures are denser than bulk silicon.

15.What is BiCMOS Technology?

It is the combination of Bipolar technology & CMOS technology.

16.What are the basic processing steps involved in BiCMOS process?

Additional masks defining P base region

> N Collector area

> Buried Sub collector (SCCD)

> Processing steps in CMOS process

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VLSI DESIGN

17.What are the advantages of CMOS process?

Low power Dissipation

High Packing density

Bi directional capability

18.What are the advantages of CMOS process? Low Input

Impedance

Low delay Sensitivity to load.

19.What is the fundamental goal in Device modeling?

To obtain the functional relationship among the terminal electrical variables of the device that is to be modeled.

20.Define Short Channel devices?

Transistors with Channel length less than 3- 5 microns are termed as Short channel devices. With short channel devices the ratio between the lateral & vertical dimensions are reduced.

21.What is pull down device?

A device connected so as to pull the output voltage to the lower supply voltage usually

0V is called pull down device.

22.What is pull up device?

A device connected so as to pull the output voltage to the upper supply voltage usually

VDD is called pull up device.

Part- B

1. Derive the CMOS inverter DC characteristics and obtain the relationship for output voltage at different region in the transfer characteristics.

Explanation (2) Diagram (2)

CMOS inverter (2) DC characteristics (5) Transfer characteristics (5)

2. Explain with neat diagrams the various CMOS fabrication technology

P-well process (4) N-well process (4)

Silicon-On-Insulator Process (4) Twin- tub Process (4)

3. Explain the latch up prevention techniques. Definition (2)


4. Explain the operation of PMOS Enhancement transistor

Explanation (2) Diagram (2) Operation (4)

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VLSI DESIGN

5. Explain the threshold voltage equation

Definition (2) Explanation (2) Derivation

Unit 2


1. Why NMOS technology is preferred more than PMOS technology?

N- channel transistors has greater switching speed when compared tp PMOS transistors.

2. What are the different operating regions foe an MOS transistor?

> Cutoff region

> Non- Saturated Region

> Saturated Region

3. What are the different MOS layers?

> n-diffusion

> p-diffusion

> Polysilicon

> Metal

4.What is Stick Diagram?

It is used to convey information through the use of color code. Also it is the cartoon of a chip layout.

5.What are the uses of Stick diagram?

> It can be drawn much easier and faster than a complex layout.

> These are especially important tools for layout built from large cells

6.Give the various color coding used in stick diagram?

> Green – n-diffusion

> Red- polysilicon

> Blue –metal

> Yellow- implant> Black-contact areas.

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VLSI DESIGN

7. Compare between CMOS and bipolar technologies.

CMOS Technology Bipolar technology

• Low static power dissipation

• High input impedance (low drive current)

• Scalable threshold voltage• High noise margin• High packing density

• High delay sensitivity to load (fan- out limitations)

• Low output drive current• Low gm (gm α Vin)

• Bidirectional capability

• A near ideal switching device

• High power dissipation

• Low input impedance (high drive current)

• Low voltage swing logic• Low packing density• Low delay sensitivity to load

• High output drive current

• High gm (gm α eVin

)

• High ft at low current• Essentially unidirectional

9.Define Threshold voltage in CMOS?

The Threshold voltage, VT for a MOS transistor can be defined as the voltage applied

between the gate and the source of the MOS transistor below which the drain to source current, IDS

effectively drops to zero.

10.What is Body effect?

The threshold volatge VT is not a constant w. r. to the voltage difference between the

substrate and the source of MOS transistor. This effect is called substrate-bias effect or body effect.

11.What is Channel-length modulation?

The current between drain and source terminals is constant and independent of theapplied voltage over the terminals. This is not entirely correct. The effective length of the conductive channel is

actually modulated by the applied VDS, increasing VDS causes the depletion region at the drain junction to grow, reducing the length of the effective channel.

12. What is Latch – up?

Latch up is a condition in which the parasitic components give rise to the establishment of low

resistance conducting paths between VDD and VSS with disastrous results. Careful control during

fabrication is necessary to avoid this problem.

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VLSI DESIGN

13. Give the basic inverter circuit.

16. Give the CMOS inverter DC transfer characteristics and operating regions

17.Define Rise time

Rise time, τr is the time taken for a waveform to rise from 10% to 90% of its steady-state value.

18. Define Fall time

Fall time, τf is the time taken for a waveform to fall from 90% to 10% of its steady-state value.

19. Define Delay time

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VLSI DESIGN

Delay time, τd is the time difference between input transition (50%) and the 50% output level. This

is the time taken for a logic transition to pass from input to output.

20. What are two components of Power dissipation.There are two components that establish the amount of power dissipated in a

CMOS circuit. These are:

i) Static dissipation due to leakage current or other current drawn continuously from the power supply.

ii) Dynamic dissipation due to

- Switching transient current

- Charging and discharging of load capacitances.

21. Give some of the important CAD tools.Some of the important CAD tools are:

i) Layout editors

ii) Design Rule checkers (DRC)

iii) Circuit extraction.

Part- B

1. Explain the silicon semiconductor fabrication process. Silicon wafer Preparation (2)

Epitaxial Growth (2) Oxidation (2) Photolithography (2) Diffusion(2)

Ion Implantation (2) Isolation technique (2) Metallization (1)

Assembly processing & Packaging (1)

2. Explain various CAD tool sets. Layout editors (4)

Design Rule checkers (DRC) (4) Circuit extraction (4)

3. Explain the operation of NMOS Enhancement transistor. Explanation (2)

Diagram (2) Operation (4)

9. Explain the Transmission gate and the tristate inverter briefly. Explanation (2)


10. Explain about the various non ideal conditions in MOS device model. Explanation (2)


UNIT 3


41.What is Verilog?

Verilog is a general purpose hardware descriptor language. It is similar in syntax to the C programming language. It can be used to model a digital system at many levels of abstraction ranging from the

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VLSI DESIGN

algorithmic level to the switch level.

42. What are the various modeling used in Verilog?

1. Gate-level modeling

2. Data-flow modeling

3. Switch-level modeling

4. Behavioral modeling

43. What is the structural gate-level modeling?

Structural modeling describes a digital logic networks in terms of the components that make up the system. Gate-level modeling is based on using primitive logic gates and specifying how they are wired together.

44.What is Switch-level modeling?

Verilog allows switch-level modeling that is based on the behavior of MOSFETs. Digital circuits at the MOS-transistor level are described using the MOSFET switches.

45. What are identifiers?

Identifiers are names of modules, variables and other objects that we can reference in the design. Identifiers consists of upper and lower case letters, digits

0 through 9, the underscore character(_) and the dollar sign($). It must be a single group of characters.

Examples:

A014, a ,b, in_o, s_out

46. What are the value sets in Verilog?

Verilog supports four levels for the values needed to describe hardware referred to as value sets.

Val u e l e v e ls Co nd i t ion in h a r d w a r e c i r c u i t s

0 Logic zero, false condition

1 Logic one, true condition

X Unknown logic value

Z High impedance, floating state

47. What are the types of gate arrays in ASIC?

1) Channeled gate arrays

2) Channel less gate arrays

3) Structured gate arrays

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VLSI DESIGN

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VLSI DESIGN

48. Give the classifications of timing control?

M e thods of timing c ont r ol :

1. Delay-based timing control

2. Event-based timing control

3. Level-sensitive timing control

T y p e s o f d e l a y - b a s e d ti m ing c ont r ol :

1. Regular delay control

2. Intra-assignment delay control

3. Zero delay control

T y p e s o f e v e n t - b a s e d ti m ing c ont r ol :

1. Regular event control

2. Named event control

3. Event OR control

4. Level-sensitive timing control

49 Give the different arithmetic operators?

O p er a t or sy m b ol

*

O p er a t ion p er f o r m e d

Multiply

N u mb e r of o pe r a nd s

Two

/ Divide Two+ Add Two- Subtract Two% Modulus Two** Power (exponent) Two

50. Give the different bitwise operators.

O p er a t or sy m b ol

~

O p er a t ion p er f o r m e d

Bitwise negation

N u mb e r of o pe r a nd s

One

& Bitwise and Two| Bitwise or Two^ Bitwise xor Two

^~ or ~^ Bitwise xnor Two~& Bitwise nand Two~| Bitwise nor Two

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VLSI DESIGN

51. What are gate primitives?

Verilog supports basic logic gates as predefined primitives. Primitive logic function keyword provide the basics for structural modeling at gate level. These primitives are instantiated like modules except that they are predefined in verilog and do not need a module definition. The important operations are and, nand, or, xor, xnor, and buf(non-inverting drive buffer).

52. Give the two blocks in behavioral modeling.

1. An initial block executes once in the simulation and is used to set up initial conditions and step-by-step data flow

2. An always block executes in a loop and repeats during the simulation.

53. What are the types of conditional statements?

1. No else statement

Syntax : if ( [expression] ) true – statement;

2. One else statement

Syntax : if ( [expression] ) true – statement;

else false-statement;

3. Nested if-else-if

Syntax : if ( [expression1] ) true statement 1;

else if ( [expression2] ) true-statement 2; else if ( [expression3] ) true-statement 3; else default-statement;

The [expression] is evaluated. If it is true (1 or a non-zero value) true-statement is executed. If it is false (zero) or ambiguous (x), the false-statement is executed.

54. Name the types of ports in Verilog

T y p e s of p o r t K e y w o r d

Input port Input Output port Output Bidirectional port inout

55. What are the types of procedural assignments?

1. Blocking assignment

2. Non-blocking assignment

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VLSI DESIGN

56. Give the different symbols for transmission gate.

57. Give the different types of ASIC.

1. Full custom ASICs

2. Semi-custom ASICs

* standard cell based ASICs

* gate-array based ASICs

3. Programmable ASICs

* Programmable Logic Device (PLD)

* Field Programmable Gate Array (FPGA).

58. What is the full custom ASIC design?

In a full custom ASIC, an engineer designs some or all of the logic cells, circuits or layout specifically for one ASIC. It makes sense to take this approach only if there are no suitable existing cell libraries available that can be used for the entire design.

59. What is the standard cell-based ASIC design?

A cell-based ASIC (CBIC) USES PREDESIGNED LOGIC CELLS KNOWN AS STANDARD CELLS. The standard cell areas also called fle4xible blocks in a CBIC are built of rows of standard cells. The ASIC designer defines only the placement of standard cells and the interconnect in a CBIC. All the mask layers of a CBIC are customized and are unique to a particular customer.

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VLSI DESIGN

60. Differentiate between channeled & channel less gate array.

C h a n n e l e d Ga t e A rr ay C h a n n e l l e ss Ga t e A rr a y

1.Only the interconnect is customized Only the top few mask layers customized

.2.The interconnect uses predefined No predefined areas are set aside for spaces routi between cells.

3.Routing is done using the spaces Routing is done using the area of transist unused.

4.Logic density is less Logic density is higher.

Part-B

11. Explain the design hierarchies. Explanation (2)

Diagram (2) Concept (2)

12. Explain the concept involved in Timing control in VERILOG. Explanation (2)

Diagram (2)

Delay-based timing control (4) Event-based timing control(4) Level-sensitive timing control(4)

13. Explain with neat diagrams the Multiplexer and latches using transmission

Gate. Explanation (2) Diagram (2) Multiplexer (4) latches(4)

14. Explain the concept of gate delay in VERILOG with example

Explanation (2) Diagram (2) Concept (2)

15. Explain the concept of MOSFET as switches and also bring the various logic gates using the switching concept .


Gate Concepts (4)

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VLSI DESIGN

UNIT 4


61. Give the constituent of I/O cell in 22V10.

2V10 I/O cell consists of

1. a register

2. an output 4:1 mux

3. a tristate buffer

4. a 2:1 input mux

It has the following characteristics:

* 12 inputs

* 10 I/Os

* product time 9 10 12 14 16 14 12 10 8

* 24 pins

62. What is a FPGA?A field programmable gate array (FPGA) is a programmable logic device that supports

implementation of relatively large logic circuits. FPGAs can be used to implement a

logic circuit with more than 20,000 gates whereas a CPLD can implement circuits of upto about 20,000

equivalent gates.

63. What are the different methods of programming of PALs? The

programming of PALs is done in three main ways:

• Fusible links

• UV – erasable EPROM

• EEPROM (E2

PROM) – Electrically Erasable Programmable ROM

64.What is an antifuse?

An antifuse is normally high resistance (>100M Ω ). On application of appropriate programming voltages,

the antifuse is changed permanently to a low-resistance structure (200-500 Ω ).

65. What are the different levels of design abstraction at physical design.

• Architectural or functional level

• Register Transfer-level (RTL)

• Logic level

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VLSI DESIGN

• Circuit level

66.What are macros?

The logic cells in a gate-array library are often called macros.

67. What are Programmable Interconnects ?

In a PAL, the device is programmed by changing the characteristics if the switching element. An alternative

would be to program the routing.

68. Give the steps inASIC design flow.

a. Design entry

b. Logic synthesisSystem partitioning c. Prelayout simulation.

d. Floorplanning e. Placement

f. Routing

g. Extraction1. Postlayout simulation

69. Give the XILINX Configurable Logic Block .

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VLSI DESIGN

70. Give the XILINX FPGA architecture

71. Mention the levels at which testing of a chip can be done?

a) At the wafer level

b) At the packaged-chip level c) At the board level

d) At the system level e) In the field

72.What are the categories of testing?

a) Functionality tests

b) Manufacturing tests

73. Write notes on functionality tests?

Functionality tests verify that the chip performs its intended function. These tests assert that all the gates in the chip, acting in concert, achieve a desired function. These tests are usually used early in the design cycle to verify the functionality of the circuit.

74. Write notes on manufacturing tests?

Manufacturing tests verify that every gate and register in the chip functions correctly. These tests are used after the chip is manufactured to verify that the silicon is intact.

75. Mention the defects that occur in a chip?

a) layer-to-layer shorts

b) discontinous wires

c) thin-oxide shorts to substrate or well

76. Give some circuit maladies to overcome the defects?

a. nodes shorted to power or ground

b. nodes shorted to each other

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VLSI DESIGN

c. inputs floating/outputs disconnected

77. What are the tests for I/O integrity?

a. I/O level test

b. Speed test

c. IDD test

78. What is meant by fault models?

Fault model is a model for how faults occur and their impact on circuits.

79. Give some examples of fault models?

a. Stuck-At Faults

b. Short-Circuit and Open-Circuit Faults

80. What is stuck – at fault?

With this model, a faulty gate input is modeled as a “stuck at zero” or “stuck at one”. These faults most frequently occur due to thin-oxide shorts or metal-to-metal shorts.

PART B

16. Explain the concept involved in structural gate level modeling and also give the description for Half adder and Full adder.


Gate Concepts (6) Half adder (3)

Full adder (3)

17. What is ASIC? Explain the types of ASIC. Definition (2)

Types (2)

Full custom ASICs (4) Semi-custom ASICs(4) Programmable ASICs(4)

18. Explain the VLSI design flow with a neat diagram

Explanation (2) Flow Diagram (2) Concepts (4)

19. Explain the concept of MOSFET as switches

Explanation (2) Diagram (2) Concepts (4)

20. Explain the ASIC design flow with a neat diagram h. Design entry(2)

i. Logic synthesisSystem partitioning(2)

j. Prelayout simulation. (2)

k. Floorplanning(2)

l. Placement(2)

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VLSI DESIGN

m. Routing(2)

n. Extraction (2)

2. Postlayout simulation(2)

UNIT 5


81. What is meant by observability?

The observability of a particular internal circuit node is the degree to which one can observe that node at the outputs of an integrated circuit.

82. What is meant by controllability?

The controllability of an internal circuit node within a chip is a measure of the ease of setting the node to a 1 or 0 state.

83. What is known as percentage-fault coverage?

The total number of nodes that, when set to 1 or 0, do result in the detection of the fault, divided by the total number of nodes in the circuit, is called the percentage-fault coverage.

84. What is fault grading?

Fault grading consists of two steps. First, the node to be faulted is selected. A simulation is run with no faults inserted, and the results of this simulation are saved. Each node or line to be faulted is set to 0 and then 1 and the test vector setis applied. If and when a discrepancy is detected between the faulted circuit response and the good circuit response, the fault is said to be detected and the simulation is stopped.

85. Mention the ideas to increase the speed of fault simulation?

a. parallel simulation

b. concurrent simulation

86. What is fault sampling?

An approach to fault analysis is known as fault sampling. This is used in circuits where it is impossible to fault every node in the circuit. Nodes are randomly selected and faulted. The resulting fault detection rate may be statistically inferred from the number of faults that are detected in the fault set and the size of the set. The randomly selected faults are unbiased. It will determine whether the fault coverage exceeds a desired level.

87. What are the approaches in design for testability?

a. ad hoc testing

b. scan-based approaches

c. self-test and built-in testing

88. Mention the common techniques involved in ad hoc testing?

a. partitioning large ckts

b. adding test points

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VLSI DESIGN

c. adding multiplexers

d. providing for easy state reset

89. What are the scan-based test techniques?

a) Level sensitive scan design

b) Serial scan

c) Partial serial scan

d) Parallel scan

90. What are the two tenets in LSSD?

a. The circuit is level-sensitive.

b. Each register may be converted to a serial shift register.

91. What are the self-test techniques?

a. Signature analysis and BILBO

b. Memory self-test

c. Iterative logic array testing

92. What is known as BILBO?

Signature analysis can be merged with the scan technique to create a structure known as BILBO- for Built In Logic Block Observation.

93. What is known as IDDQ testing?

A popular method of testing for bridging faults is called IDDQ or current- supply monitoring. This relies on the fact that when a complementary CMOS logic gate is not switching, it draws no DC current. When a bridging fault occurs, for some combination of input conditions a measurable DC IDD will flow.

94. What is boundary scan?

The increasing complexity of boards and the movement to technologies like multichip modules and surface-mount technologies resulted in system designers agreeing on a unified scan-based methodology for testing chips at the board. This is called boundary scan.

95. What is the test access port?

The Test Access Port (TAP) is a definition of the interface that needs to be included in an IC to make it capable of being included in a boundary-scan architecture. The port has four or five single bit connections, as follows:

• TCK(The Test Clock Input)• TMS(The Test Mode Select)• TDI(The Test Data Input)• TDO(The Test Data Output)

• TRST*(The Test Reset Signal)

96.. What are the contents of the test architecture?

The test architecture consists of:• The TAP interface pins• A set of test-data registers• An instruction register• A TAP controller

97. What is the TAP controller?

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VLSI DESIGN

The TAP controller is a 16-state FSM that proceeds from state to state based on the TCK and TMS signals. It provides signals that control the test data registers, and the instruction register. These include serial-shift clocks and update clocks.

98. What is known as test data register?

The test-data registers are used to set the inputs of modules to be tested, and to collect the results of running tests.

99. What is known as boundary scan register?

The boundary scan register is a special case of a data register. It allows circuit-board interconnections to be tested, external components tested, and the state of chip digital I/Os to be sampled.

PART B

21. a) Explain fault models.

Stuck-At Faults Definition (2) Diagram (2)

Short-circuit and Open-circuit faults

Definition (2) Diagram (2)

b) Explain ATPG.

Definition (2) Truth tables (2)

Five valued logic (2) Testability measures (2)

22. Briefly explain

a) Fault grading & fault simulation

Fault grading (2) Fault simulation (2)

b) Delay fault testing Diagram (2) Description (2)

c) Statistical fault analysis Definition (1) Statistics (3)

d) Fault sampling (4)

23. Explain scan-based test techniques.

Level sensitive scan design (4) Serial scan (4)

Partial serial scan (4) Parallel scan (4)

24. Explain Ad-Hoc testing and chip level test techniques.

Ad-Hoc testing

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VLSI DESIGN

Parallel-load feature (2) Test signal block (2) Use of the bus (2)

Use of multiplexer (2) Chip level test techniques

Definition (2)

Regular logic arrays (2) Memories (2)

Random logic (2)

25. Explain self-test techniques and IDDQ testing.

Signature analysis and BILBO (6) Memory-self test (4)

Iterative logic array testing (3) IDDQ testing (3)

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DIGITAL COMMUNICATION

Digital Communication

UNIT I- SAMPLING AND WAVEFORM


1. Define Dirac comb or ideal sampling function. What is its Fourier Transform?

Dirac comb is nothing but a periodic impulse train in which the impulses are spaced b y a time interval of Ts

seconds. The equation for the function is given by

2. Give the interpolation formula for the reconstruction of the original signal g (t) from the sequence of

sample values g(n/2W).

Where 2W is the bandwidth

n is the number of samples

3. State sampling theorem.

If a finite –energy signal g(t) contains no frequencies higher than W hertz it is completely determined by

specifying its co=ordinates at a sequence of points spaced 1/2W seconds apart.

If a finite energy signal g(t) contains no frequencies higher than W hertz, it may be completely recovered

from its co=ordinates at a sequence of points spaced 1/2W seconds apart.

4. Define quardrature sampling

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Quardrature sampling is used for uniform sampling of band pass signals

The in-phase component gr(t) and the quardrature component gQ(t) may be obtained by multiplying the band

pass signal

Respectively and then suppressing the sum-frequency components b y means of appropriate low pass filter.

Under the assumption that fc>W, we find that gr(t) and gQ(t) are both low-pass signals limited to -W<f<W.

Accordingly each component may be sampled at the rate of 2W samples per second. This type of sampling is

called quardrature sampling.

5. What is aliasing?

The phenomenon of a high-frequency in the spectrum of the original signal g (t) seemingly taking on the

identity of a lower frequency in the spectrum of the sampled signal g (t) is called aliasing or fold over.

7. What is meant b y PCM?

Pulse code modulation (PCM) is a method of signal coding in which the message signal is sampled; the

amplitude of each sample is rounded off to the nearest one of a finite set of discrete levels and encoded so that

both time and amplitude are represented in discrete form. This allows the message to be transmitted by means

of a digital waveform.

8. Define quantizing process

The conversion of analog sample of the signal into digital form is called quantizing process

9. What are the two fold effects of quantizing process?

1. The peak-to-peak range of input sample values subdivided into a finite set of decision levels or

decision thresholds

2. The output is assigned a discrete value selected from a finite set of representation levels are

reconstruction values that are aligned with the treads of the staircase.

10. What is meant by idle channel noise?

Idle channel noise is the coding noise measured at the receiver output with zero transmitter input.

11. What is meant b y prediction error?

The difference between the actual sample of the process at the time of interest and the predictor output

is called a prediction error.

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12. Define delta modulation.

Delta modulation is the one-bit version of differential pulse code modulation.

13. Define adaptive delta modulation

The performance of a delta modulator can be improved significantly by making the step size of the

modulator assume a time- varying form. In particular during a steep segment of the input signal the step size is

increased. Conversely when the input signal is varying slowly, the step is reduced, In this way, the step size is

adapting to the level of the signal. The resulting method is called adaptive delta modulation.

14. Name the types of uniform quantizer?

1. Mid tread type quantizer.

2. Mid riser type quantizer.

15. Define mid tread quantizer.

Origin of the signal lies in the middle of a tread of the staircase.

16. Define mid-riser quantizer?

Origin of the signal lies in the middle of a riser of the stair case

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17. Define quantization error.

Quantization error is the difference between the output and input values of quantizer.

18. What you mean by non-uniform quantization?

Step size is not uniform. Non-uniform quantizer is characterized by a step size that increases as the

separation from the origin of the transfer characteristics is increased. Non-uniform quantization is otherwise

called as robust quantization

19. Draw the quantization error for the mid tread and mid-rise type of quantizer?

For mid tread type:

For mid riser type:

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20. What is the disadvantage of uniform quantization over the non-uniform quantization?

SNR decreases with decrease in input power level at the uniform quantizer but non-uniform quantization

maintains a constant SNR for wide range of input power levels. This type of quantization is called as robust

quantization

21. What do you mean by companding? Define compander

The signal is compressed at the transmitter and expanded at the receiver. This is called as companding.

The combination of a compressor and expander is called a compander.

22. Draw the block diagram of compander? Mention the types of companding?

Types of companding:

1. µ law companding

2. A law companding

23. What is PAM?

PAM is the pulse amplitude modulation. In pulse amplitude modulation, the amplitude of a carrier

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consisting of a periodic train of rectangular pulses is varied in proportion to sample values of a message signal.

24. What is the need for speech coding at low bit rates?

The use of PCM at the standard rate of 64 Kbps demands a high channel bandwidth for its

transmission ,so for certain applications, bandwidth is at premium, in which case there is a definite need for

speech coding at low bit rates, while maintaining acceptable fidelity or quality o f reproduction

25. Define ADPCM

It means adaptive differential pulse code modulation, a combination of adaptive quantization and

adaptive prediction. Adaptive quantization refers to a quantizer that operates with a time varying step size. The

autocorrelation function and power spectral density of speech signals are time varying functions of the respective

variables. Predictors for such input should be time varying. So adaptive predictors are used.

Part: B

1. Drive the expression for the sampling process in time domain.

2. What are all the types of sampling technique and explain about any two.

3. a. Explain the generation of PPM and PWM with neat circuit diagram.

b. Explain the quantization process with PCM block diagram.

4. Write brief notes on 1) TDM

2) FDM

5. Compare DM with ADM and explain linear prediction filter.

UNIT II BANDLIMITED SIGNALLING


26. What is meant b y forward and backward estimation?

AQF: Adaptive quantization with forward estimation. Unquantized samples of the input signal are used

to derive the forward estimates.

AQB: Adaptive quantization with backward estimation. Samples of the quantizer output are used to

derive the backward estimates.

APF: Adaptive prediction with forward estimation, in which unquantized samples of the input signal are

used to derive the forward estimates of the predictor coefficients

26


APB: Adaptive prediction with backward estimation, in which Samples of the quantizer output and the

prediction error are used to derive estimates o f the predictor coefficients

27. What are the limitations of forward estimation with backward estimation?

Side information

Buffering

Delay

28. How are the predictor coefficients determined?

For the adaptation of the predictor coefficients the least mean square (LMS) algorithm is used.

29. Define adaptive sub band coding?

It is a frequency domain coder, in which the speech signal is divided in to number of sub bands and each

one is coded separately. It uses non masking phenomenon in perception for a better speech quality. The noise

shaping is done by the adaptive bit assignment.

30. What are formant frequencies?

In the context of speech production the formant frequencies are the resonant frequencies of the vocal

tract tube. The formants depend on the shape and dimensions of the vocal tract.

31. What is the bit rate in ASBC?

Nfs = (MN) (fs/M)

Nfs - >bit rate

M ->number of sub bands of equal bandwidths

N ->average number of bits

Fs / M -> sampling rate for each sub band

32. Define Adaptive filter?

It is a nonlinear estimator that provides an estimate of some desired response without requiring

knowledge of correlation functions, where the filter coefficients are data dependent. A popular filtering algorithm

is the LMS algorithm.

33. Define data signaling Rate.

Data signaling rate is defined as the rate measured in terms bits per second (b/s) at which data are

transmitted.

Data signaling rate Rb=I/Tb

Where Tb=bit duration

27


34. Define modulation rate.

It is defined as the rate at which signal level is changed depending On the nature of the format used to

represent the digital data. It is measured in Bauds or symbols per second

35. State NRZ unipolar format

In this format binary 0 is represent by no pulse and binary 1 is represented by the positive pulse.

36. State NRZ polar format

Binary 1 is represented by a positive pulse and binary 0 is represented by a Negative pulse

37. State NRZ bipolar format.

Binary 0 is represented by no pulse and binary one is represented by the alternative positive and

negative pulse.

38. State Manchester format.

Binary 0: The first half bit duration negative pulse and the second half Bit duration positive pulse

Binary 1: first half bit duration positive pulse and the second half Bit duration negative pulse

39. What is an eye pattern?

Eye Pattern is used to study the effect of inter symbol interference.

40. What is the width of the eye?

It defines the time interval over which the received waveform can be sampled without error from inter

symbol interference.

41. What is sensitivity of an eye?

The sensitivity of the system to timing error is determined by the rate of closure of the eye as the

sampling time is varied.

42. What is margin over noise?

The height of the eye opening at a specified sampling time defines the margin over noise.

43. What is Inter symbol interference?

The transmitted signal will undergo dispersion and gets broadened during its transmission through the

channel. So they happen to collide or overlap with the adjacent symbols in the transmission. This overlapping is

called Inter Symbol Interference.

44. How eye pattern is obtained?

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The eye pattern is obtained by applying the received wave to the vertical deflection plates of an

oscilloscope and to apply a saw tooth wave at the transmitted symbol rate to the horizontal deflection plate.

Part: B

1. Derive the expression for the matched filter and prove any one property.

2. Prove the effect ISI using necessary block diagram and design.

3. Write brief notes on Nyquist’s criterion for distortion less base band binary transmission.

4. Explain the six array PAL transmission.

5. Why do we adoptive equalizer and design any one type of adoptive equalizer.

UNIT III PASS BAND DATA TRANSMISSION


45. Properties of matched filter.

The signal to noise ratio of the matched filter depends only upon the ratio of the signal energy to the psd

of white noise at the filter input

The output signal of a matched filter is proportional to a shifted version of the autocorrelation function of

the input signal to which the filter is matched.

46. Why do we go for Gram-Schmidt Orthogonalization procedure?

Consider a message signal m. The task of transforming an incoming message mi=1,2,…..M, into a

modulated wave si(t) may be divided into separate discrete time & continuous time operations. The

justification for this separation lies in the Gram-Schmidt orthogonalization procedure which permits the

representation of any set of M energy signals, si(t), as linear combinations of N orthonormal basis functions,

where N= M

47. What is matched filter receiver?

A filter whose impulse response is a time reversed & delayed version of some signal Ø

j (t) then it is said to be matched to Ø j (t) correspondingly, the optimum receiver based on the detector is

referred to as the matched filter receiver.

48. What is maximum likelihood detector?

Maximum likelihood detector computes the metric for each transmitted message compares them and

then decides in favor of maximum. The device for implementing the decision rule

29


i.e.; set ^m = mi if

In [fx (x/mk)] is maximum for k=i is called max imum –likelihood detector and the decision rule is called

maximum likelihood.

49. Define antipodal signals.

Pair of sinusoidal signals that differ only in a phase shift of 180 degrees are referred to as antipodal

signals

50. Ex plain how QPSK differs from PSK in term of transmission bandwidth and bit information it

carries?

For a given bit rate 1/Tb, a QPSK wave requires half the transmission bandwidth of the

corresponding binary PSK wave. Equivalently for a given transmission bandwidth, a QPSK wave carries

twice as many bits of information as the corresponding binary PSK wave.

51. Give the equation for average probability of symbol error for coherent binary PSK

Average probability of signal error,

Pe = 1 / 2 erfc vEb / No

52. Give the signal space characterization of QPSK

53. Define QPSK

QPSK is Quadriphase –shift keying. In QPSK the phase of the carrier takes on one of the four

equally spaced values Such as /4, /4, /4, /4 .

54. Define Dibit

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A unique pair o f bits is called a dibit. Gray encoded set of dibits 10, 00, 01 & 11.

55. Give the transmitted signal of Non-coherent binary FSK

56. Give the two basic operation of DPSK transmitter.

1. Differential encoding of the input binary wave

2. Phase –shift keying hence, the name differential phase shift keying

57. Define deviation ratio in MSK.

The parameter h is defined by

h= Tb(f1-f2)

h is deviation ratio, measured with respect to bit rate 1/Tb

58.Define MSK signal in interval 0<t<Tb

59. What is nominal carrier frequency in MSK?

Nominal carrier frequency is the arithmetic mean of the two frequencies f1 and f2 and it is given as,

F1is the frequency for symbol –1

F2is the frequency for symbol –0

60. What are the three broad types of synchronization?

1. Carrier synchronization

2. Symbol & Bit synchronization

3. Frame synchronization.

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61. What is carrier synchronization?

The carrier synchronization is required in coherent detection methods to generate a coherent reference

at the receiver. In this method the data bearing signal is modulated on the carrier in such a way that the power

spectrum of the modulated carrier signal contains a discrete component at the carrier frequency.

62. What are the two methods for carrier synchronization?

1. Carrier synchronization using Mth Power loop

2. Costas loop for carrier synchronization

63. What is called symbol or bit synchronization?

In a matched filter or correlation receiver, the incoming signal is sampled at the end of one bit or

symbol duration. Therefore the receiver has to know the instants of time at which a symbol or bit is

transmitted. That is the instants at which a particular bit or symbol status and when it is ended. The

estimation of these times of bit or symbol is called symbol or bit synchronization.

64. What are the two methods of bit and symbol synchronization?

1. Closed loop bit synchronization

2. Costas loop for carrier synchronization

65. What are the disadvantages of closed loop bit synchronization?

1) If there is a long string of 1’s and o’s then y(t) has no zero crossings and synchronization

may be lost.

2) If zero crossing of y(t) are not placed at integer multiples of Tb, the synchronization suffers

from timing Jitter.

66. What is called frame synchronization?

Depending on bits used for encoding, the word length is defined. Thus each word container

some fixed number of bits. The receiver has to know when a particular frame status and when its individual

message bits status. This type of synchronization is called frame synchronization.

67. Why synchronization is required?

The signals from various sources are transmitted on the single channel by multiplexing. This requires

synchronization between transmitter and receiver Special synchronization bits are added in the

transmitted signal for the purpose Synchronization is also required for detectors to recover the digital

data properly from the modulated signal.

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Part: B

1. Derive the expression for the BPSK technique.

2. Explain the MFSK and derive the pe.

3. Draw the space diagram of MSK and explain about the same.

4. Derive the error probability expression for the MPSK.

5. Compare the all types of Pass band transmission.

33


UNIT IV ERROR CONTROL CODING


68. What is linear code?

A code is linear if the sum of any two code vectors produces another code vector.

69. What is code rate?

Code rate is the ratio of message bits (k) and the encoder output bits (n). It is defined b y r (i.e.) r= k/N.

70. Define code efficiency

It is the ratio of message bits in a block to the transmitted bits for that block by the encoder i.e.

71. What is hamming distance?

The hamming distance between two code vectors is equal to the number of elements in which they differ.

For example let the two code vectors be X= (101) and Y= (110)

These two code vectors differ in second and third bits.

Therefore the hamming distance between x and Y is two.

72. What is meant b y systematic & non-systematic code?

In a systematic block code, message bit appear first and then check bits.

In the non-systematic code, message and check bits cannot be identified in the code vector

73. How syndrome is calculated in Hamming codes and cyclic codes?

In hamming codes the syndrome is calculated as,

S = YHT

Here Y is the received and HT is the transpose of parity check matrix

In cyclic code, the syndrome vector polynomial is given as,

S (P) = remainder (y (p)/ G (P))

34


y (P) is received vector polynomial and G (p) is generator polynomial

74. What is BCH Code?

BCH codes are most extensive and powerful error correcting cyclic code The decoding of BCH coder is

comparatively simpler. For any positive integer ‘m’ and‘t’, there exists a BCH code with following parameters.

Block length n = 2m-1

No. of parity check bits: n-k<mt

Minimum distance: dmin>2t+1

75. What are the conditions to satisfy the hamming code?

1) No. of Check bits q>3

2) Block length n = 2q-1

3) No of message bits K = n-q

4) Minimum distance dmin =3

76. Define code word & block length.

The encoded block of ‘n’ bits is called code word. The no. of bits ‘n’ after coding is called block length.

77. Give the parameters of RS codes.

Reed Solomon codes. These are non binary BCH codes

Block length = n =2 m-1 symbols

Message size: k symbols

Parity check size: n-k= 2t symbols

Minimum distance, dmin =2t +1 symbols

78. Why RS codes are called maximum distance separable codes?

(n,k) Linear block code for which the minimum distance equals n – k + 1 is called maximum distance separable

codes. For RS code minimum distance equals.

79. What are Golay codes?

Golay code is the (23, 12) cyclic code whose generating polynomial is,

This code has a minimum distance of dmin=7. This code can correct upto 3 errors. It is perfect code.

35


80. What are the advantages of cyclic codes?

1. Encoders and decoders for cyclic codes are simple

2. Cyclic codes also detect error burst that span many successive bits.

Part: B

1. Explain the channel coding technique used in the Block codes.

2. What are all the message vectors can be extracted from the code vector that was generated by 1+X+X3.

3. Explain the Viterbi algorithm for the detection of any two message vectors (One Word) from the code vectors

that were generated by (111), (101) and (011).

4. Explain the construction of Block Code and explain how error syndrome is calculated.

5. Explain in detail about orthogonal codes, Biorthogonal codes and Transorthogonal codes.

UNIT V SPREAD SPECTRUM SYSTEMS


81. Define pseudo-noise (PN) sequence.

A pseudo-noise sequence is defined as a coded sequence of 1s and Os with certain autocorrelation

properties. It is used in spread Spectrum communications It is periodic in that a sequence of 1s and 0s

repeats itself exactly with a known period.

82. What does the term catastrophic cyclic cod e represent?

‘000’ is not a state of the shift register sequence in PN sequence generator, since this results in a

catastrophic cyclic code i.e once the 000 state is entered, the shift register sequence cannot leave this state.

83. Define a random binary sequence.

A random binary sequence is a sequence in which the presence of a binary symbol 1 or 0 is equally

probable.

84. State the balance property of random binary sequence.

In each period of a maximum length sequence, the number of 1s is always one more than the number of

0s. This property is called the balance property

85. Mention about the run property.

Among the runs of 1s and 0s in each period of a maximum length sequence, one half the runs of each

36


kind are of length one, one fourth are of length two, one eighth are of length three, and so or as long as these

function represent meaningful numbers of runs. This property is called the run property.

86. Give the correlation property of random binary sequence

The autocorrelation function of a maximum length sequence is periodic and binary valued. This property

is called the correlation property

87. Mention the significance of spread spectrum modulation

An important attribute of spread-spectrum modulation is that it can provide protection against externally

generated interfering (jamming) signals with finite power. The jamming signal may consist of a fairly powerful

broadband noise or multitone waveform that is directed at the receiver for the purpose of disrupting

communications. Protection against jamming waveforms is provided by purposely making the information

bearing signal occupy a bandwidth far in excess of minimum bandwidth necessary to transmit it.

88. What is called processing gain?

Processing Gain (PG) is defined as the ratio of the bandwidth of spread message signal to the bandwidth

of unspreaded data signal i.e.).

89. What is called jamming effect?

In the frequency band of the interest, somebody else transmits the signals intentionally since

these signals the in the frequency band of transmission, they interface the required signal. Hence it

becomes difficult to detect the required signals. This is called jamming effect

90. What is Anti jamming?

With the help of spread spectrum method, the transmitted signals are spread over the mid

frequency band. Hence these signals appear as noise. Then it becomes difficult for the jammers to send

jamming signals. This is called anti jamming.

91. What are the three codes used for the anti jamming application?

1. Golay code (24, 12)

2. Ex purgated Golay (24, 11)

3. Maximum length shift register code

37


92. What is called frequency hop spread spectrum?

In frequency hop spread spectrum, the frequency of the carrier hops randomly from one frequency to

another frequency

93. What is slow frequency hopping?

If the symbol rate of MFSK is an integer multiple of hop rate (multiple symbols per hop) then it is called

slow frequency hopping

94. What is fast frequency hopping?

If the hop rate is an integer multiple of symbol rate (multiple hops per symbol) then it is called

fast frequency hopping.

95. What are the two function of fast frequency hopping?

1. Spread Jammer over the entire measure of the spectrum of Txed signal

2. Retuning the Jamming signal over the frequency band of Txed signal

96. What are the features of code Division multiple Accesses?

1. It does not require external synchronization networks

2. CDMA offers gradual degradation in performance when the no. of users is increased but it is easy to add

new user to the system

3. If offers an external interference rejection capability

97. What is called multipath Interference?

The interference caused by the interfacing of the signal form the indirect path with the signal of

direct path is called multipath interference.

98. What is the advantage of a spread spectrum technique?

The main advantage of spread spectrum technique is its ability to reject interference whether it

be the unintentional interference of another user simultaneously attempting to transmit through the

channel (or) the intentional interference of a hostile transmitter to jam the transmission.

99. What is called frequency hop spread spectrum?

In frequency hop spread spectrum, the frequency of the carrier hops randomly from one frequency

to another frequency.

100 .What is slow frequency hopping?

If the symbol rate of MFSK is an integer multiple of hop rate (multiple symbols per hop) then it is

called slow frequency hopping.

38


Part: B

1. Generate the PN sequence for [5, 4, 3, and 1] and prove the all properties of the same.

2. List out and prove the Properties of the PN sequence.

3. Explain the concept of DS/BPSK.

4. List out the uses of the FH. Explain the FH techniques with the frequency spectrum.

5. Write shorts notes on

1. Probability Error.

2. Jamming Margin

3. (S/N) of the DS System.

39

ANTENNA AND WAVE PROPAGATION

Antenna And Wave Propagation

UNIT I


1. Define an antenna.

Antenna is a transition device or a transducer between a guided wave and a free space wave

or vice versa. Antenna is also said to be an impedance transforming device.

2. What is meant by radiation pattern?

Radiation pattern is the relative distribution of radiated power as a function of distance in space .It is a

graph which shows the variation in actual field strength of the EM wave at all points which are at equal distance from the antenna. The energy radiated in a particular direction by

an antenna is measured in terms of FIELD STRENGTH.(EVolts/m)

3. Define Radiation intensity?

The power radiated from an antenna per unit solid angle is called the radiation intensity U (watts per

steradian or per square degree). The radiation intensity is independent of distance.

4. Define Beam efficiency?

The total beam area ( WA) consists of the main beam area ( WM ) plus the minor lobe area ( Wm) .

Thus WA = WM+ Wm .

The ratio of the main beam area to the total beam area is called beam efficiency.

Beam efficiency = SM = WM / WA.

5.Define Directivity?

The directivity of an antenna is equal to the ratio of the maximum power density P(q,f)max to its

average value over a sphere as observed in the far field of an antenna.

D = P(q,f)max / P(q,f)av. Directivity from

Pattern.

D = 4p / WA. . Directivity from beam area(WA ).

40


6.What are the different types of aperture.?

i) Effective aperture.

ii). Scattering aperture.

iii) Loss aperture.

iv) collecting aperture.

v). Physical aperture.

7.Define different types of aperture.?

Effective aperture(Ae).

It is the area over which the power is extrated from the incident wave and delivered to the load is called effective aperture.

Scattering aperture(As.)

It is the ratio of the reradiated power to the power density of the incident wave.

Loss aperture. (Ae).

It is the area of the antenna which dissipates power as heat.

Collecting aperture. (Ae).

It is the addition of above three apertures.

Physical aperture. (Ap).

This aperture is a measure of the physical size of the antenna.

8. Define Aperture efficiency?

The ratio of the effective aperture to the physical aperture is the aperture efficiency. i.e

Aperture efficiency = hap = Ae / Ap (dimensionless).

9. What is meant by effective height?

The effective height h of an antenna is the parameter related to the aperture.It may be defined as

the ratio of the induced voltage to the incident field.i.e H= V / E.

10. What are the field zone?

The fields around an antenna ay be divided into two principal regions.

i. Near field zone (Fresnel zone)

41


ii. Far field zone (Fraunhofer zone)

11.What is meant by Polarization.?

The polarization of the radio wave can be defined by direction in which the electric vector E is aligned during the passage of atleast one full cycle.Also polarization can also be defined the physical orientation of the radiated electromagnetic waves in space.The polarization are three types. They are Elliptical polarization ,circular polarization and linearpolarization.

12. What is meant by front to back ratio.?

It is defined as the ratio of the power radiated in desired direction to the power radiated in the opposite

direction. i.e FBR = Power radiated in desired direction / power radiated in the opposite direction.

13. Define antenna efficiency.?

The efficiency of an antenna is defined as the ratio of power radiated to the total input power supplied to the antenna.

Antenna efficiency = Power radiated / Total input power

14. What is radiation resistance ?

The antenna is a radiating device in which power is radiated into space in the form of electromagnetic wave.W’ = I2 R Rr = W’/ I2 Where Rr is a fictitious resistance called called as radiation resistance.

15 What is meant by antenna beam width?

Antenna beamwidth is a measure of directivity of an antenna. Antenna beam width is an angular width in

degrees, measured on the radiation pattern (major lobe) between points where the radiated power has fallen to half its maximum value .This is called as “beam width” between half power points or half power beam

width.(HPBW).

16. What is meant by reciprocity Theorem.?

If an e.m.f is applied to the terminals of an antennano.1 and the current measured at the terminals of the

another antenna no.2, then an equal current both in amplitude and phase will be obtained at the terminal of

the antenna no.1 if the same emf is applied to the terminals of antenna no.2.

17.What is meant by isotropic radiator?

A isotropic radiator is a fictitious radiator and is defined as a radiator which radiates fields uniformly in all

directions. It is also called as isotropic source or omni directional radiator or simply unipole.

18. Define gain

42


The ratio of maximum radiation intensity in given direction to the maximum radiation intensity from a

reference antenna produced in the same direction with same input power.

19. Define self impedance

Self impedance of an antenna is defined as its input impedance with all other antennas are completely

removed i.e away from it.

20 . Define mutual impedance

The presence of near by antenna no.2 induces a current in the antenna no.1 indicates that presence of antenna no.2 changes the impedance of the antenna no.1.This effect is called mutual coupling and results in mutual impedance.

Part-B

1. Explain the retarded vector potential in detail.2. Derive an expression for the power radiated by the current element and calculate the radiation resistance. 3. Derive an expression for the far field component of a half wave dipole of an antenna.4. a) Derive the total power radiated by half wave dipole.b) Show that the radiation resistance of a half wave dipole is 80?2 (dl/?)2 Ohms.5. Explain the reciprocity theorem in detail.

UNIT 2


21. What is meant by cross field.?

Normally the electric field E is perpendicular to the direction of wave propagation. In some situation the

electric field E is parallel to the wave propagation that condition is called Cross field.

22.Define axial ratio

The ratio of the major to the minor axes of the polarization ellipse is called the Axial Ratio. (AR).

23. What is meant by Beam Area.?

The beam area or beam solid angle or WA of an antenna is given by the normalized power pattern over a sphere.

24. What is duality of antenna.?

43


It is defined as an antenna is a circuit device with a resistance and temperature on the one hand and the

space device on the other with radiation patterns, beam angle ,directivity gain and aperture.

25.State Poynting theorem.

It states that the vector product of electric field intensity vector E and the magnetic filed intensity vector

H at any point is a measure of the rate of energy flow per unit area at that point.The direction of power flow is perpendicular to both the electric field and magnetic field components.

26.What is point source?

It is the waves originate at a fictitious volumeless emitter source at the center ‘O’ of the observation circle.

27.What is meant by array.?

An antenna is a system of similar antennas oriented similarly to get greater directivity in a desired direction.

28.What is meant by uniform linear array.?

An array is linear when the elements of the array are spaced equally along the straight line. If the elements are fed with currents of equal magnitude and having a uniform progressive phase shift along the line, then it is called uniform linear array .

29.What are the types of array.?

a. Broad side array.

b. End fire array

c. Collinear array.

d. Parasitic array.

30.What is Broad side array.?

Broad side array is defined as an arrangement in which the principal direction of radiation is perpendicular

to the array axis and also the plane containing the array element.

31.Define End fire array.?

End fire array is defined as an arrangement in which the principal direction of radiation is coincides with

the array axis.

32. What is collinear array.?

In this array the antenna elements are arranged coaxially by mounting the elements end to end in straight

line or stacking them one over the other with radiation pattern circular symmetry. Eg. Omnidirectional antenna.

44


33. What is Parasitic array.?

In this array the elements are fed parasitically to reduce the problem of feed line. The power is given to one

element from that other elements get by electro magnetic coupling. Eg. Yagi uda antenna.

34. What is the condition on phase for the end fire array with increased directivity.?

This condition will be referred to as the condition for increased directivity.

35.Define array factor.

The normalized value of the total field.The field is given by the expression E will be referred to as array factor.

36. Define beam width of major lobe?

It is defined the angle between the first nulls (or) it is defined as twice the angle between the first null and the major lobe maximum direction.

37. List out the expression of beam width for broad side array and end fire array.

For broad side array the expression for beam width between the first nulls is given by

38. Differentiate broad side and End fire array.?

Broad side array

End fire array

1. Antennas fed in Phase __

2. Maximum Radiation is

Perpendicular to the direction of array axis.

3. Beam width of major lobe is twice the

Antenna elements are fed of out of Phase _ _- _G

Maximum Radiation directed along the array axis.Beam width is greater thanthat for a broad side array of same length.

39.What is the need for the Binomial array.?

The need for a binomial array is

i). In uniform linear array as the array length is increased to increase the directivity, the secondary lobes

also occurs.

ii) For certain applications, it is highly desirable that secondary lobes should be eliminated completely or

45


reduced to minimum desirable level compared to main lobes.

40. Define power pattern.?

Graphical representation of the radial component of the pointing vector Sr at a constant radius as

a function of angle is called power density pattern or power pattern.

41. What is meant by similar Point sources.?

Whenever the variation of the amplitude and the phase of the field with respect to the absolute angle for any two sources are same then they are called similar point sources. The maximum amplitudes of the individual sources may be unequal.

PART B6. Derive an expression for the electric field and magnetic field due to a current element at a distance point in free space.7. a) Derive an expression for the gain of half wave dipole.b) Explain effective aperture area with its types in detail.8. At what distance in ?, is the radiation component of magnetic field twice the inductance component ? At what distance is it 100 times. 9. Write short notes on various forms of arraysi.Broad side array ii.End fire arrayiii.Collinear array iv.Parasitic array10. Derive the expression for the far field pattern of an array of 2 – isotropic point sourcesi) Equal amplitude and phase ii) Equal amplitude and opposite phaseiii) Unequal amplitude and any phase

UNIT 3


42. What is meant by identical Point sources.?

Similar point sources with equal maximum amplitudes are called identical point sources.

43. What is the principle of the pattern multiplication?

The total field pattern of an array of non isotropic but similar sources is the product of the

i) individual source pattern and

ii) The array pattern of isotropic point sources each located at the phase center of the individual

source having the same amplitude and phase. While the total phase pattern is the sum of the phase

patterns of the individual source pattern and array pattern.0

44.What is the advantage of pattern multiplication?

46


™_Useful tool in designing antenna ™_It approximates the pattern of a complicated array

without making lengthy computations

45.What is tapering of arrays?

Tapering of array is a technique used for reduction of unwanted side lobes .The amplitude of currents in the

linear array source is non-uniform; hence the central source radiates more energy than the ends. Tapering is done from center to end.

46.What is a binomial array?

It is an array in which the amplitudes of the antenna elements in the array are arranged according to the

coefficients of the binomial series.

47.What are the advantages of binomial array?

Advantage: ™_No minor lobes

Disadvantages: ™_Increased beam width ™_Maintaining the large ratio of current

amplitude in large arrays is difficult

48.What is the difference between isotropic and nonisotropic

source

™_Isotropic source radiates energy in all directions but non-isotropic source radiates energy only in some desired directions. ™_Isotropic source is not physically realizable but non-isotropic source is physically realizable.

49.Define Side Lobe Ratio

Side Lobe Ratio is defined as the ratio of power density in the principal or main lobe to the power density of the longest minor lobe.

50. List the arrays used for array tapering ™

_Binomial Array:Tapering follows the coefficient of binomial series

™Dolph Tchebycheff Array: Tapering follows the coefficient of Tchebycheff polynomial

51.What is a Short Dipole?

Ans: A short dipole is one in which the field is oscillating because of the oscillating voltage and current.It

is called so, because the length of the dipole is short and the current is almost constant throughtout the entire length of the dipole.It is also called as Hertzian Dipole which is a hypothetical antenna and is defined as a short isolated conductor carrying uniform alternating current.

52.How radiations are created from a short Dipole?

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Ans:The dipole has two equal charges of opposite sign oscillating up and down in a harmonic

motion.The charges will move towards each other and electric filed lines were created.When the charges meet at the midpoint, the field lines cut each other and new field are created.This process is spontaneous and so more fields are created around the antenna.This is how radiations are obtained from a short dipole.(See Figure from John. D .Kraus Book)

53.Why a short dipole is also called an elemental dipole?

A short dipole that does have a uniform current will be known as the elemental dipole.Such a dipole will generally be considerably shorter than the tenth wave length maximum specified for a short dipole.Elemental dipole is also called as elementary dipole,elementary doublet and hertzian dipole.

54.What is a Infinitesimal Dipole?

When the length of the short dipole is vanishingly small,then such a dipole is called a infinitesimal dipole.If dl be the infinitesimally small length and I be the current,then Idl is called as the current element.

55.Why a short dipole is called a oscillating dipole?

A short dipole is initially in neutral condition and the moment a current starts to flow in one direction,one

half of the dipole require an excess of charge and the other a deficit because a current is a flow of electrical

charge.Then ,there will be a voltage between the two halves of the dipole.When the current changes its direction this charge unbalance will cause oscillations.Hence an oscillating current will result in an oscillating voltage.Since,in such dipole,electric charge oscillates ,it may be called as Oscilllating electric dipole.

56.What do you understand by retarded current?

Since,the short electric dipole is so short,the current which is flowing through the dipole is

assumed to be constant throughtout its length.The effect of this current is not felt instantaneous at a distance point only after an interval equal to the time required for the wave to propagate over the distance r is called the retardation time

57.Define induction field

The induction field will predominate at points close to the current element ,where the distance from the

centre of the dipole to the particular point is less.This field is more effective in the vicinity of the current element only.It represents the energy stored in the magnetic field surrounding the current element or conductor.This field is also known as near field.

58.Define Radiation field

The radiation field will be produced at a larger distance from the the current element ,where the distance

from the centre of the dipole to the particular point is very large.It is also called as distant field or far field.

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59.At what distance from the dipole is the induction field equal to the radiation field?

As the distance from the current element or the short dipole increases ,both induction and radiation fields

emerge and start decreasing .However,a distance reaches from the conductor at which both the induction and radiation field becomes equal and the particular distance depends upon the wavelength.

60.Define Radiation Resistance

It is defined as the fictitious resistance which when inserted in series with the antenna will consume the same amount of power as it is actually radiated.The antenna appears to the transmission line as a resistive component and this is known as the radiation resistance.

PART B

1. Explain the principle of Pattern multiplication.2. Explain the array of N- sources of equal amplitude and spacing- Broad side casei. Direction of pattern maxima ii. Direction of pattern minimaii. Beam width of major lobe3. Explain the array of N- sources of equal amplitude and spacing- End fire casei) Direction of pattern maxima ii. Direction of pattern minimaii) Beam width of major lobe

4. Write short notes oni. Binomial arrays ii. Phased arrays

5. Explain the principle of traveling wave radiator

UNIT 4


61.Give the expression for the effective aperture of a short dipole

Refer John. D .Kraus Book(p.297)

62.What is a dipole antenna?

A dipole antenna may be defined as a symmetrical antenna in which the two ends are at equal potential relative to the midpoint.

63.What is a half wave dipole?

A half wave antenna is the fundamental radio antenna of metal rod or tubing or thin wire which has a physical length of half wavelength in free space at the frequency of operation

64.Give the expression for the effective aperture of a Half wave Dipole

Refer John. D .Kraus Book(p.298)

65.What is the radiation resistance of a half wave dipole

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The radiation resistance of a half wave dipole is given by Rr=73 ohm

66.What is a loop antenna?

A loop antenna is a radiating coil of any convenient cross-section of one or more turns carrying radio frequency current.it may assume any shape (e.g. rectangular,square,triangular and hexagonal)

67.Give an expression of radiation resistance of a small loop

Radiation resistance of a small loop is given by Refer John. D .Kraus Book(p.366)

68.How to increase the radiation resistance of a loop antenna

The radiation resistance of a loop antenna can be increased by:

1. increasing the number of turns

2. inserting a ferrite core of very high permeability with loop antenna’ s circumference which will rise the magnetic field intensity called ferrite loop.

69.What are the types of loop antennas?

Loop antennas are classified as Refer John. D .Kraus Book(p.266)

70.What are Electrically Small loop antennas?

Electrically Small loop antennas is one in which the overall length of the loop is less than one-tenth of the wavelength. Electrically Small loop antennas have small radiation resistances that are usually smaller than their loop resistances.They are very poor radiators and seldom employed for transmission in radio communication.

71.What are Electrically large loop antennas?

Electrically Large loop antennas is one in which the overall length of the loop approaches the wavelength.

72.List out the uses of loop antenna

Various uses of loop antenna are:

™_It is used as receiving antenna in portable radio and pagers

™_It is used as probes for field measurements and as directional antennas for radio wave navigation

™_It is used to estimate the direction of radio wave propagation

73.What are the parameters to be considered for the design of an helical antenna?

The parameters to be considered for the design of an helical antenna are:

1. Bandwidth

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2. Gain

3. Impedance

4. Axial Ratio

74.What are the types of radiation modes of operation for an helical antenna

The two types of radiation modes of operation possible for an helical antenna are:

1. Normal mode of operation

2. Axial mode of operation

75.Which antenna will produce circularly polarized waves

Helical antenna radiates circularly polarized wave.

76.List the applications of helical antenna

The applications of helical antenna are:

It became thw workhouse of space communications for telephone,television and data,being employed both on satellites and at ground stations Many satellites including weather satellites,data relay satellites all have helical antennas

It is on many othe probes of planets and comets,including moon and mars,being used alone,in arrays or as feeds for parabolic reflectors,its circular polarization and high gain and simplicity making it effective for space application

77.Define Sky wave.

Waves that arrive at the receiver after reflection in the ionosphere is called sky wave.

78.Define Tropospheric wave.

Waves that arrive at the receiver after reflection from the troposphere region is called Tropospheric wave.(ie 10 Km from Earth surface).

79. Define Ground wave.

Waves propagated over other paths near the earth surface is called ground wave propagation.

80.What are the type of Ground wave.

Ground wave classified into two types.

i. Space wave

ii. Surface wave.

PART B

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2. Derive an expression for the radiated field due to a TWA.3. Obtain the expression for the field produced by TWA and compare its radiation with resonant antenna.4. Obtain the expression for the emf due to loop antenna and explain its use as a Direction finder.5. Explain the special features of various types of Horn antennas and frequency independent antennas.6. With a suitable diagram, discuss the construction and operation of a Yagi antenna.7. Write detailed notes on (a) Parabolic reflectors (b) Log Periodic antennas8. (a) Explain the principle of operation and applications of folded dipoles.(b) With a suitable diagram explain the construction and principle of operation of a log – periodic antenna.9. Write short notes on (a) Slot radiators (b) Loop antennas10. How does a log periodic antenna provide a large bandwidth of operation?11. Explain the principle of operation and applications of loop antenna.12. Write detailed notes on (a) Horn antennas (b) Frequency independent antennas.13. Explain the principle of operation and applications of loop antenna

UNIT 5


81 What is meant by Space Wave.?

It is made up of direct wave and ground reflected wave. Also includes the portion of energy received as a result of diffraction around the earth surface and the reflection from the upper atmosphere.

82. What is meant by Surface Wave.?

Wave that is guided along the earth’ s surface like an EM wave is guided by a transmission is called surface

wave. Attenuation of this wave is directly affected by the constant of earth along which it travels.

83. What is meant by fading.?

Variation of signal strength occur on line of sight paths as a result of the atmospheric conditions and it is

called .It can not be predicted properly.

84. What are the type of fading.?

Two types. i. Inverse bending.

iii. Multi path fading.

85. What is inverse and multi path fading.?

Inverse bending may transform line of sight path into an obstructed one.

Multi path fading is caused by interference between the direct and ground reflected waves as well as

interference between two are more paths in the atmosphere.

86.What is meant by diversity reception.?

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To minimize the fading and to avoid the multi path interference the technique used are diversity

reception. It is obtained by two ways.

i. Space diversity reception.

ii. Frequency diversity reception.

iii. Polarization diversity.

87. Define Space diversity Reception.

This method exploits the fact that signals

received at different locations do not fade together and the antenna which high signal strength at the moment dominates.

88 .Define frequency diversity Reception.

This method takes advantage of the fact that signals of slightly different frequencies do not fade

synchronously. This fact is utilized to minimize fading in radio telegraph circuits.

89. Define polarization diversity reception.

It is used in normally in microwave links, and it is found that signal transmitted over the same path in two

polarizations have independent fading patterns.in broad band dish antenna system, Polarization diversity combined with frequency diversity reception achieve excellent results.

90. What is meant by Faraday’ s rotation.?

Due to the earth’ s magnetic fields, the ionosheric medium becomes anisotropic and the incident

plane wave entering the ionosphere will split into ordinary and extra ordinary waves/modes.

When these modes re-emerge from the ionosphere they recombine into a single plane wave again.

Finally the plane of polarization will usually have changed, this phenomenon is known as Faraday’ s

rotation.

91. What are the factors that affect the propagation of radio waves.?

i. Curvature of earth.

ii. Earth’ s magnetic field.

iii. Frequency of the signal.

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iv. Plane earth reflection.

92. Define gyro frequency.

Frequency whose period is equal to the period of an electron in its orbit under the influence of the

earths magnetic flux density B.

93. Define critical frequency.

For any layer , the highest frequency that will be reflected back for vertical incidence is

fcr = 9¥1max

94. Define Magneto-Ions Splitting.

The phenomenon of splitting the wave into two different components (ordinary and extra-ordinary) by

the earths magnetic field is called Magneto-Ions Splitting.

95.Define LUHF.

The lowest useful HF for a given distance and transmitter power is defined as the lowest frequency

that will give satisfactory reception for that distance and power.

It depends on

i. The effective radiated power

ii. Absorption character of ionosphere for the paths between transmitter and receiver.

iii. The required field strength which in turn depends upon the radio noise at the receiving location and type of service involved .

96. Define Refractive index.

It is defined as n = c / vp

Velocity of light

in vaccun =Phase velocity inthe medium n = ¥ r

97.Define maximum Usable Frequency.

The maximum Frequency that can be reflected back for a given distance of transmission is called

the maximum usable frequency (MUF) for that distance.

98. Define skip distance.

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The distance with in which a signal of given frequency fails to be reflected back is the skip

distance for that frequency.The higher the frequency the greater the skip distance.

99. Define Optimum frequency.?

Optimum frequency for transmitting between any two points is therefore selected as some frequency

lying between about 50 and 85 percent of the predicted

maximum usable frequency between those points.

PART B 1.Explain in detail the working principle of Helical antenna in (a) Normal mode (b) Axial mode 2.Explain in detail the design aspects of Microstip antenna.

3. Describe the methods for measuring the gain and beam width of antenna.

4.Describe the methods for measuring the Power gain, Radiation efficiency and Transmission bandwidth of an antenna.

5. Describe the Slotted line technique for Impedance measurement. 6. Describe how the radiation pattern and Radiation resistance of a given antenna can be measured experimentally. 7. Derive the relation between oblique and vertical incidence transmission. 8. Write short notes on Vertical incidence measurement of the ionosphere. 9. Write short notes on Oblique incidence measurement of the ionosphere. 10.Describe briefly about Polarization measurements. 11.Derive an expression to determine Antenna efficiency and Antenna Aperture. 12.Derive an expression to determine the Directivity of an antenna.

55

MICROCONTROLLER AND RISC ARCHITECTURE

MICRO CONTROLLERS AND RISC ARCHITECTURE

UNIT I


1. Define microcomputer.

A system designed using microprocessor as its CPU is called a microcomputer.

2. What is the function of microprocessor in a system?

The microprocessor is the master in the system, which controls all the activity of the system. It issues address and control signals and fetches the instruction and data from

memory. Then it executes the instruction to take appropriate action.

3. List the applications of microcomputer.

Personal computing, calculators, small business system,control applications and instrumentation systems.

4. What do you mean by 8-bit Mention some systems in each type.

The processors are classified into 8-bit and 16-bit depending on the basic data size handled by the ALU of the processor.

8-bit microprocessors: 8085

5. What is ALE?

The ALE (address latch enable) is a signal used to demultiplex the address and data lines, using an external latch. It is used to enable the external latch.

6. Explain the function of IO/M in 8085?

The IO/M is used to differentiate memory access and I/O access.For IN and OUT instruction it is high.For memory reference instructions it is low.

7. What is a flag?

Flag is a flip-flop used to store the information about the status of the processor and the status of the instruction executed most recently. There are five flags in 8085.They are sign flag, zero flag, auxiliary carry flag, parity flag and carry flag.

8. What are the hardware interrupts of 8085?give its priority.

The hardware interrupts in 8-85 are TRAP, RST 7.5,RST 6.5 and RST 5.5.The TRAP has the highest priority, followed by RST 7.5,RST 6.5, RST 5.5 and INTR.

9. What is assembly language?

The language in which the mnemonics are used to write a program is called assembly language. The mnemonics are short hand form of the instructions and which is given by the manufacturers of microprocessor.

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10. What is processor cycle (Machine cycle)

The processor cycle is the basic operation performed by the processor. To execute an instruction, the processor will run one or more machine cycles in a particular order.

11. What is instruction cycle?

The sequence of operations that a processor has to carry out while executing the instruction is called instruction cycle. Each instruction cycle of a processor in turn consists of a number of machine cycles.

12. What is the need for timing diagram?

The timing diagram provides information regarding the status of various signals, when a machine cycle is executed. The knowledge of timing diagram is essential for system designer to select matched peripheral devices like memories, latches, ports etc.

13. What is interrupt acknowledge cycle?

The interrupt acknowledge cycle is a machine cycle executed by 8085 processor to get the address of the interrupt service routine inorder to service the interrupted device.

14. How many instructions are available in 8085 instruction set?

The 8085 instruction set consists of 74 basic instructions and 246 total instructions.

15. What is addressing?

The method of specifying the data to be operated by the instruction is called addressing.

16. What is the function performed by SIM instruction?

The SIM (set interrupt mask0 instruction is used to mask the hardware interrupts RST 7.5,RST 6.5 and RST 5.5.The execution of SIM instruction outputs the content of the accumulator to define interrupt mask bits and also used to output serial data on the SOD line.

17. What is the function performed by RIM instruction?

The RIM (Read Interrupt mask) instruction is used to check whether an interrupt is masked or not. It is also used to read data from SID line.

18. What is the function of HLT and NOP instruction?

HLT- used to suspend program execution. NOP-used for producing software delay and reserve memory spaces for future software modifications.

19. What is the need for port?

The I/O devices are generally slow devices and their timing characteristics do not match with processor timings.hence the I/O devices are connected to system bus through the ports.The port is nothing but a buffered IC which is used to hold the data transmitted from the microprocessor to I/O device or vice-versa.

20. What is an interrupt?

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Interrupt is a signal send by an external device to the processor so as to request the processor to perform a particular task or work.

PART-B

1. With a neat sketch discuss the architecture of Intel 8085.

2. Explain the pin diagram and flag register of 8085.

3. Discuss the operation performed by the following 8085 instructions. Specify the addressing modes

4. Explain the machine control instructions in 8085.

5. Explain the addressing modes of 8085.

UNIT 2


21. What is vectored and Non-vectored interrupt?

When an interrupt is accepted, if the processor control branches to a specific address defined by the manufacturer then the interrupt is called vectored interrupt. In non-vectored interrupt there is no specific address for storing the interrupt service routine. Hence the interrupter device should give the address of the interrupt service routine.

22. What is polling?

Polling is a scheme or algorithm to identify the devices interrupting the processor. polling is employed when multiple devices interrupt the processor through one interrupt pin of the processor.

23. What are the different types of polling?

The polling can be classified into software and hardware polling. In software

polling the entire polling process is govern by a program. In hardware polling, the

hardware takes care of checking the status of interrupting devices and allows one by one

to the processor.

25. How clock signal is generated in 8086?what is the maximum internal clock frequency

of 8086?

The 8086 do not have on-chip clock generation circuit. Hence the clock

generation chip,8284 is connected to CLK pin of 8086.the clock signal supplied by 8284

is divided by three for internal use. the maximum internal clock frequency is 5MHz.

26. What is pipelined architecture?

In pipelined architecture the processor will have number of functional units and

the execution time of functional units are overlapped. Each functional unit works

independently most of the time.

28. What is the difference between segment register and general-purpose register?

The segment registers are used to store 16-bit segment base address of the four

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memory segments. The general-purpose registers are used s the source or destination

register during data transfer and computations, as pointers to memory and as counters.

29. What are the control bits used in IC 8086?

The flags TF,IF and DF of 8086 are used to control the processor operation and

so they are called control bits.

30. What are the minimum mode signals used in 8086?

The minimum mode signals used in 8086 are DT/R, DEN, ALE, M/IO, WR,

INTA, HOLD and HLDA.

31. What is queue? How queue is implemented in 8086?

A data structure, which can be accessed on the basis of first in first out, is called

queue. The 8086 have six numbers of 8-bit FIFO registers, which is used for instruction

queue.

32. Give any two difference between 8085 and 8086 processor.

8085 8086

It is a 8 bit processor It is a 16 bit processor

It contains 16 address lines It contains 20 address lines

33. Give any two processors that supports pipelining?

Intel 8085 and Motorola 68000.

34. What is microcontroller?

Microcontroller is a microprocessor with limited number of RAM, ROM,I/O ports

and timer on a single chip. i.e., all the required hardware for a system is combined

together on a single chip.

35. Mention any two real time microcontrollers.

· Micro oven

· Washing machine

36. What are the bits used in the program status word of 8031 microcontroller?

The various status bits used are the carry bit, auxiliary carry bit, overflow bit,

parity bit, general purpose flag bit and register select bank control bits.

37. What is the use of PSEN signal used in IC 8031?

It is the control signal that enables the external program memory. When the

device executes the program from external program memory PSEN is activated.

During the execution of internal program memory PSEN is not activated.

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38. What are the registers used for timer operations?

The registers used for timer operation are TH0, TH1, TL0, TL1, TMOD, TCON

and IE.

39. What is the difference between mode 0 and mode 1 timer operation of IC8031?

In mode 0 13 bits register is used whereas in mode1 16 bits register is used.

40. What is meant by transition activated interrupts?

In transition activated interrupts, the timer control register bits are set when the

transition at the INT input.(changes from logic 1 to 0 or vice versa).

PART B

6. Draw the timing diagram of ADI and LDA instructions.

7. Draw the timing diagram of LXI rp,d16 and XTHL instructions.

8. Draw the timing diagram of PUSH and DAD instructions.

9. Draw the timing diagram of STAX rp and IN instructions.

10. Draw the timing diagram of JMP and RST instructions.

UNIT 3


41. What is the use of MOVC and MOVX instructions?

MOVC-used to move the data from code (program) memory to accumulator.

MOVX-used to move the data from external memory to the accumulator.

42. Give any two differences between LCALL and ACALL instruction.

Long call(LCALL) Absolute call(ACALL)

3 byte instruction 2byte instruction

Issues 11 bit absolute addressing It addresses full 64 Kbytes

43. List some assembler directives used by the compiler of 8031.

· ORG

· EQU

· DFB

44. What is the basic difference between counter and timer?

In the case of timer operation counter is connected to the internal clock where as

in counter operation it is connected to the external clock having different baud rates.

45. What is use of DPTR in 8031 microcontroller?

It consists of a high byte and low byte data of a 16-bit external data RAM address.

It is accessed as a 16 bit register or 2,8 bit registers.

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46. What are the basic digital output units used in microcomputer?

A simple system uses 7-segment LED displaysfor numbers and hexadecimal

letters,18-segment LED display or 5 x 7 matrix LED displays for displaying numbers

and letters of an alphabet.

47. Why the seven segment LED display is referred as static display?

In this circuit the current is passed through the display at all times,and hence it is

referred as static display.

48. What are the interface devices used to connect output port and high power devices?

Integrated circuit buffers and transistor buffers are used as interface devices

between the output port pins and high power devices.

49. What is the disadvantage in keyboard interfacing using ports?

The disadvantage in keyboard interfacing using ports is that most of the processor time is utilized in keyboard scanning and debouncing.As a result the computational speed of the processor will be reduced.

50. What is the advantage in using INTEL 8279 for keyboard and display interfacing?

When 8279 is used for keyboard and display interfacing, it takes care of all the task involved in keyboard scanning and display refreshing. Hence the processor is relieved from the task of keyboard scanning, debouncing, keyboard generation and display refreshing and the processor time can be more effectively used fro computing.

51. What is a programmable peripheral device?

If the functions performed by a peripheral device can be altered or changed by a

program instruction then the peripheral device can be altered or changed by a program

instruction then the peripheral device is called programmable device.

52. What is synchronous data transfer scheme?

In synchronous data transfer scheme, the processor does not check the readiness

of the device after a command have been issued for read/write operation in this scheme

the processor will request the device to get ready and then read/write to the device

immediately after the request.

53. What is asynchronous data transfer scheme?

In asynchronous data transfer scheme, first the processor sends a request to thes

device for read/write operation. Then the processor keeps on polling the status of the

device. Once the device is ready, the processor execute a data transfer instruction to

complete the process.

54. What are the operating modes of 8255?

The port of 8255 can be programmed to work in any one of the following

operating modes as input or output port.

Mode-0 : simple I/O port

Mode-1 :handshake I/O port.

Mode-2 : bi-directional I/O port

55. What are the functions performed by port-C of 8255

· the port-C pins are used for handshake signals.

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· Port-C can be used as an 8-bit parallel I/O port in mode-0

· It can be used as two numbers of 4-bit parallel port in mode-0

· The individual pins of port-C can be set or reset for various control

applications.

56. What is USART?

The device which can be programmed to perform synchronous or asynchronous

serial communication is called USART(Universal Synchronous Asynchronous Receiver

Transmitter).The INTEL 8251 is an example of USART.

57. What are the functions performed by INTEL 8251?

The INTEL 8251 is used for converting parallel data to serial or viceversa.the data

transmission or reception can be either asynchronous or synchronous. The 8251 can be

used to interface MODEM and or synchronously. The 8251 can be used to interface

MODEM and establish serial communication through MODEM over telephone lines.

58. What are the control words of 8251 and what are its functions?

The control words of 8251 are mode word and command word. The mode word

informs 8251 about the baud rate, character length, parity and stop bits .The command

word can be send to enable the data transmission and reception.

59. What are the information that can be obtained from the status word of 8251?

The CPU to check the readiness of the transmitter or receiver and to check the

character synchronization in synchronous reception can read the status word. It also

provides information regarding various errors in the data received .The various error

conditions that can be checked from the status word are the parity error, overrun error and

framing error.

60. What is baud rate?

The baud rate at which the serial data are transmitted. Baud rate is defined as

1/(the time for a bit cell).In some systems one bit cell has one data bit, then the baud rate

and bits/sec are same.

PART B

11. Explain 8086 in detail.

12. Explain the addressing modes of 8086.

13. Explain the data transfer instructions of 8086.

14. Explain the arithmetic instructions of 8086.

15. Explain the logical instructions of 8086.

UNIT 4


61. What are the different types of data transfer scheme?

The different types of data transfer transfer scheme are

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· Synchronous u data transfer scheme.

· Asynchronous data transfer scheme

· Interrupt driven data transfer scheme.

62. What are the different types of DMA data transfer scheme?

The different types of DMA data transfer scheme are

· Cycle stealing DMA

· Block or burst mode DMA

· Demand transfer mode DMA

63. What is the need for interrupt controller?

The interrupt controller is employed to expand the interrupt inputs. It can handle

the interrupt request from various devices and allow one by one to the processor.

64. List some of the features of INTEL 8259?

· It manage eight interrupt request

· The interrupt vector addresses are programmable

· The priorities of interrupts are programmable.

· The interrupt can be masked or unmasked individually.

65. Write the various functional blocks of INTEL 8259?

The various functional blocks of 8259 are control logic, read/write logic, data bus

buffer, interrupt request register, in service register, interrupt mask register, priority

resolver and cascade buffer.

66. How 8259 is programmed?

The 8259 is programmed by sending initialization command words(ICW’s) and

operational command words(OCW’s).

67. What are the features of 8259 that can be programmed using OCW’s?

The OCW’s are used to program the following features of 8259

· masking of individual interrupts

· specific on nonspecific end of interrupt

· priority modes

68. What are the different scan modes of 8279?

The different scan modes of 8279 are decoded scan and encoded scan and

encoded scan. In decoded scan, the output of scan lines will be similar to a 2-to-4

decoder. In encoded scan mode, the output of scan lines will be binary count, and so an

external decoder should be used to convert the binary count to decoded output.

69. What are the different programmed data transfer schemes used in microprocessor?

The various data tranfer schemes are

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· Synchronous data transfer

· Asynchronous data transfer(hand shaking)

· Interrupt driven data transfer

70. What are the two various modes of DMA transfer?

· Burst mode

· Cycle stealing

71. What is meant by control word?

The content of control register is called as control word or command word. It

specifies the various mode of operations, I/O functions of the port etc.

72. What is Microprocessor ? What are the basic units of a microprocessor ?

It is a program controlled semiconductor device (IC, which fetches, decode

and executes instructions.

The basic units or blocks of a microprocessor are ALU, an array of registers

and control unit.

73. What is multiplexing and what is its advantage? How the address and data lines are

demultiplexed in 8085?

Multiplexing is transferring different information at different well defined

times through same lines. A group of such lines is called multiplexed bus. The

advantage of multiplexing is that fewer pins are required for microprocessors to

communicate with outside world.

The low order address and data lines of 8085 are demultiplexed using an external

8-bit D-Latch (74LS373) and the ALE signal of 8085.

At the beginning of every machine cycle, ALE is asserted high and then low. Also

the low byte of address is given out through ADo -AD7 lines. Since the ALE is

connected to Enable of Latch, when ALE is asserted high and then low the addresses

are latched into the output lines of the latch. Now the lines ADo -AD7 are free for

data transfer.

74. Define mnemonics.

The short-hand form of describing the instructions are called mnemonics. The

mnemonics are given by the manufacturers of microprocessors and programmable

devices.

75. List the various machine cycles of 8085

The various machine cycles of8085 are

(i) Opcode fetch cycle

(ii) Memory read cycle

(iii) Memory write cycle

(iv) I/O read cycle

(v) I/O write cycle

(vi) Interrupt acknowledge cycle

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(vii) Bus idle cycle.

76. What is the need for timing diagram?

The timing diagram provides information regarding the status of various signals,

when a machine cycle is executed. The knowledge of timing diagram is essential for

system designer to select matched peripheral devices like memories, latches, ports, etc.,

to form a microprocessor system.

77. What is T -state?

The T-state is the time period of the internal clock signal of the processor. The

time taken by the processor to execute the machine cycle is expressed in T-state.

78. Define opcode and operand.

Opcode (Operation code) is the part of an instruction / directive that identifies a

specific operation.

Operand is a part of an instruction / directive that represents a value on which

the instruction acts.

79. What are the various addressing modes available in 8085?

The 8085 has the following five different types of addressing.

1. Immediate addressing

2. Direct addressing

3. Register addressing

4. Register indirect addressing

5. Implied addressing

PART B

16. What are the sources of Interrupt in 8086?

17. (i) Write a program for conversion of Binary to BCD with algorithm and flowchart.

(ii) Write a program for conversion of BCD to Binary with algorithm and flowchart.




UNIT 5


83. Give the alternate functions for the port pins of port3?

RD WR T1 T0 INT1 INT0 TXD RXD

RD – Read data control output.

WR – Write data control output.

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T1 – Timer / Counter1 external input or test pin.

T0 – Timer / Counter0 external input or test pin.

INT1- Interrupt 1 input pin.

INT 0 – Interrupt 0 input pin.

TXD – Transmit data pin for serial port in UART mode.

RXD - Receive data pin for serial port in UART mode.

84. Write down the different operating modes for serial communication of 8051.

Serial communication of 8051 operate under four modes. They are

mode 0 , mode 1, mode 2 and mode3 .SM0 and SM1 bits of SCON register

specifies the mode.

SM0 SM1 Mode

0 0 0 Baud rate fixed.

0 1 1 8-bit data, 1 stop bit, 1 start bit. Baud rate

variable.

1 0 2 8-bit data, 9th programmable bit,1 stop bit, 1

start bit, Baud rate fixed.

1 1 3 8-bit data, 9th programmable bit,1 stop bit, 1

start bit, Baud rate variable.

8. Write the flags of 8086.

The 8086 has nine flags and they are

1. Carry Flag (CF) 6. Overflow Flag (OF)

2. Parity Flag (PF) 7. Trace Flag (TF)

3. Auxiliary carry Flag (AF) 8. Interrupt Flag (IF)

4. Zero Flag (ZF) 9. Direction Flag (DF)

5. Sign Flag (SF)

87. What is handshake port ? Explain the working of a handshake input port and output

port.

In handshake port, signals are exchanged between I/O device and port or

port and processor for checking or informing various condition of the device.

In handshake input operation, the input device will check whether the port is empty or

not. If the port is empty then it will load data to port. When the port receives the data, it

will inform the processor for read operation. Once the data have been read by the

processor, the port will signal the input device that it is empty. Now the input device can

load another data to port and the above process is repeated.

In handshake output operation, the processor will load a data to port. When the

port receives the data, it will inform the output device to collect the data. Once the

output device accepts the data, the port will inform the processor that it is empty. Now

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the processor can load another data to port and the above process is repeated.

88. What is debouncing ?

When a key is, pressed it bounces for a short time. If a key code is generated

immediately after sensing a key actuation, then the processor will generate the same

keycode a number of times.(A key typically bounces for 10 to 20 msec). Hence the

processor has to wait for the key bounces to settle before reading the keycode. This

process is called keyboard debouncing.

89. What are the different types of ADC?

The different types of ADC are successive approximation ADC, counter type

ADC flash type ADC, integrator converters and voltage-to-frequency converters.

90. What is meant by memory mapping? What is memory access time ?

The memory mapping is the process of interfacing memories to

microprocessor and allocating addresses to each memory locations. The memory

access time is the time taken by the processor to read or write a memory location.

During read operation it is the time between a valid address on the bus and end of

read control signal. During write operation it is the time between a valid

address on the bus and the end of write control signal.

91. What is an Interrupt ? How the interrupt are classified ?

Interrupt is a signal send by an external device to the processor so as to

request the processor to perform a particular task or work.

They are three methods of classifying interrupts

Method I :The interrupts are classified into Hardware and

Software interrupts

Method II:The interrupts are classified into vectored and Non-

Vectored interrupt

92. Explain the function of the pins PSEN and EA of 8051.

PSEN :

PSEN stands for program store enable. In 8051 based system in

which an external ROM holds the program code, this pin is connected to the OE pin of

the ROM.

EA :

EA stands for external access. When the EA pin is connected to

Vcc, program fetched to addresses 0000H through 0FFFH are directed to the internal

ROM and program fetches to addresses 1000H through FFFFH are directed to external

ROM/EPROM. When the EA pin is grounded, all addresses fetched by program are

directed to the external ROM/EPROM.

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93. Explain the 16-bit registers DPTR and SP of 8051.

DPTR:

DPTR stands for data pointer. DPTR consists of a high byte (DPH) and a low byte

(DPL). Its function is to hold a 16-bit address. It may be manipulated as a 16-bit data

register or as two independent 8-bit registers. It serves as a base register in indirect

jumps, lookup table instructions and external data transfer.

SP:

SP stands for stack pointer. SP is a 8- bit wide register. It is incremented before

data is stored during PUSH and CALL instructions. The stack array can reside anywhere

in on-chip RAM. The stack pointer is initialized to 07H after a reset. This causes the

stack to begin at location

08H.

94. Name the special functions registers available in 8051.

a. Accumulator

b. B Register

c. Program Status Word.

d. Stack Pointer.

e. Data Pointer.

f. Port 0

g. Port 1

h. Port 2

i. Port 3

j. Interrupt priority control register.

k. Interrupt enable control register.

95. Name the five interrupt sources of 8051?.

The interrupts are:

Vector address

· External interrupt 0 : IE0 : 0003H

· Timer interrupt 0 : TF0 : 000BH

· External interrupt 1 : IE1 : 0013H

· Timer Interrupt 1 : TF1 : 001BH

· Serial Interrupt

Receive interrupt : RI : 0023H

Transmit interrupt: TI : 0023H

96. List the features of 8051 microcontroller?

The features are

*single_supply +5 volt operation using HMOS technology.

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*4096 bytes program memory on chip(not on 8031)

*128 data memory on chip.

*Four register banks.

*Two multiple mode,16-bit timer/counter.

*Extensive boolean processing capabilities.

*64 KB external RAM size

*32 bidirectional individually addressible I/O lines.

*8 bit CPU optimized for control applications.

97. What are the modes in which 8086 can operate?

The 8086 can operate in two modes and they are minimum ( or

uniprocessor) mode and maximum ( or multiprocessor) mode.

98. What is the difference between segment register and general purpose register?

The segment registers are used to store 16 bit segment base address of the

four memory segments. The general purpose registers are used as the source or

destination register during data transfer and computation, as pointers to memory

and as counters.

99. What is a programmable peripheral device ?

If the functions performed by a peripheral device can be altered or

changed by a program instruction then the peripheral device is called

programmable device. Usually the programmable devices will have control

registers. The device can be programmed by sending control word in the

prescribed format to the control register.

100. What are the operating modes of port -A 8255?

The port-A of 8255 can be programmed to work in anyone of the

following operating modes as input or output port.

Mode-0 : Simple 1/0 port.

Mode-l: Handshake 1/0 port

Mode-2 : Bidirectional 1/0 port

101. What are the functions performed by port-C of 8255?

1. The port-C pins are used for handshake signals.

2. Port-C can be used as an 8-bit parallel 1/0 port in mode-0.

3. It can be used as two numbers of 4-bit parallel port in mode-0.

4. The individual pins of port-C can be set or reset for various control

applications.

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102. What are the different scan modes of of8279?

The different scan modes of8279 are decoded scan and encoded scan. In

decoded scan mode, the output of scan lines will be similar to a 2-to-4 decoder. In

encoded scan mode, the output of scan lines will be binary count, and so an

external decoder should be used to convert the binary count to decoded output.

PART B


22. Explain the architecture of 8051.

23. List the various Instruction available in 8051 microcontroller.

24. Draw the Pin Diagram of 8051 and explain the function of various signals.

25. Write a program to multiply two BCD numbers in 8051.

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DIGITAL IMAGE PROCESSING

Digital Image Processing

UNIT I


1. Define Image?

An image may be defined as two dimensional light intensity function f(x, y)

where x and y denote spatial co-ordinate and the amplitude or value of f at any point

(x, y) is called intensity or grayscale or brightness of the image at that point.

2. What is meant by pixel?

A digital image is composed of a finite number of elements each of which has a

particular location or value. These elements are referred to as pixels or image elements or picture elements or pels elements.

3. Define Digital image?

When x, y and the amplitude values of f all are finite discrete quantities , we call

the image digital image.

4. What are the steps involved in DIP?

1. Image Acquisition

2. Preprocessing

3. Segmentation

4. Representation and Description

5. Recognition and Interpretation

5. What is recognition and Interpretation?

Recognition means is a process that assigns a label to an object based on the

information provided by its descriptors.

Interpretation means assigning meaning to a recognized object.

6. Specify the elements of DIP system?

1. Image Acquisition

2. Storage

3. Processing

4. Display

7. Explain the categories of digital storage?

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1. Short term storage for use during processing.

2. Online storage for relatively fast recall.

3. Archical storage for infrequent access.

8. What are the types of light receptors?

The two types of light receptors are

1. Cones and

2. Rods

9. Differentiate photopic and scotopic vision?

hotopic vision cotopic vision

1. The human being can

resolve the fine details with these cones because each one is connected to its own nerve end.

2. This is also known as bright light vision.

everal rods are

onnected to one nerve end. So it gives the overall

picture of the image.

This is also known as thin light vision.

10. How cones and rods are distributed in retina?

In each eye, cones are in the range 6-7 million and rods are in the range 75-150

million.

11. Define subjective brightness and brightness adaptation?

Subjective brightness means intensity as preserved by the human visual system.

Brightness adaptation means the human visual system can operate only from scotopic to glare limit. It cannot operate over the range simultaneously. It accomplishes this large variation by changes in its overall intensity.

12. Define weber ratio

The ratio of increment of illumination to background of illumination is called as

weber ratio.(ie) ∆i/i

If the ratio (∆i/i) is small, then small percentage of change in intensity is needed

(ie) good brightness adaptation.

If the ratio (∆i/i) is large , then large percentage of change in intensity is needed

(ie) poor brightness adaptation.

13. What is meant by machband effect?

Machband effect means the intensity of the stripes is constant. Therefore it

preserves the brightness pattern near the boundaries, these bands are called as machband effect.

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14. What is simultaneous contrast?

The region reserved brightness not depend on its intensity but also on its

background. All centre square have same intensity. However they appear to the eye to become darker as the background becomes lighter.

15. What is meant by illumination and reflectance?

Illumination is the amount of source light incident on the scene. It is represented as i(x, y).

Reflectance is the amount of light reflected by the object in the scene. It is represented by r(x, y).

16. Define sampling and quantization

Sampling means digitizing the co-ordinate value (x, y). Quantization means digitizing the amplitude value.

17. Find the number of bits required to store a 256 X 256 image with 32 gray levels?

32 gray levels = 25

= 5 bits

256 * 256 * 5 = 327680 bits.

18. Write short notes on neighbors of a pixel.

The pixel p at co-ordinates (x, y) has 4 neighbors (ie) 2 horizontal and 2 vertical neighbors whose co-ordinates is given by (x+1, y), (x-1,y), (x,y-1), (x, y+1). This is called as direct neighbors. It is denoted by N4(P)

Four diagonal neighbors of p have co-ordinates (x+1, y+1), (x+1,y-1), (x-1, y-1),

(x-1, y+1). It is denoted by ND(4).

Eight neighbors of p denoted by N8(P) is a combination of 4 direct neighbors and

4 diagonal neighbors.

19. Explain the types of connectivity.

1. 4 connectivity

2. 8 connectivity

3. M connectivity (mixed connectivity)

20. What is meant by path?

Path from pixel p with co-ordinates (x, y) to pixel q with co-ordinates (s,t) is a sequence of distinct pixels with co-ordinates.

21. Give the formula for calculating D4 and D8 distance.

D4 distance ( city block distance) is defined by

D4(p, q) = |x-s| + |y-t|

D8 distance(chess board distance) is defined by

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D8(p, q) = max(|x-s|, |y-t|).

22. What is geometric transformation?

Transformation is used to alter the co-ordinate description of image. The basic geometric transformations are

1. Image translation

2. Scaling

3. Image rotation

23. What is image translation and scaling?

Image translation means reposition the image from one co-ordinate location to another along straight line path.

Scaling is used to alter the size of the object or image (ie) a co-ordinate system is scaled by a factor.

24. What is the need for transform?

The need for transform is most of the signals or images are time domain signal (ie) signals can be measured with a function of time. This representation is not always best. For most image processing applications anyone of the mathematical transformation are applied to the signal or images to obtain further information from that signal.

25. Define fourier transform pair?

The fourier transform of f(x) denoted by F(u) is defined by

∝

F(u)= ∫ f(x) e-j2πux

dx ----------------(1)

-∝

The inverse fourier transform of f(x) is defined by

∝

f(x)= ∫F(u) ej2πux

dx --------------------(2)

-∝

The equations (1) and (2) are known as fourier transform pair.

26. Define fourier spectrum and spectral density?

Fourier spectrum is defined as

F(u) = |F(u)| e jφ(u)

Where

|F(u)| = R2

(u)+I2

(u)

φ(u) = tan-1

(I(u)/R(u))

Spectral density is defined by p(u) = |F(u)|2

p(u) = R2

(u)+I2

(u)

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27. Give the relation for 1-D discrete fourier transform pair?

The discrete fourier transform is defined by

n-1

F(u) = 1/N ∑ f(x) e –j2πux/N

x=0

The inverse discrete fourier transform is given by

n-1

f(x) = ∑ F(u) e j2πux/N

x=0

These equations are known as discrete fourier transform pair.

28. Specify the properties of 2D fourier transform.

The properties are

1. Separability

2. Translation

3. Periodicity and conjugate symmetry

4. Rotation

5. Distributivity and scaling

6. Average value

7. Laplacian

8. Convolution and correlation

9. sampling

29. Explain separability property in 2D fourier transform

The advantage of separable property is that F(u, v) and f(x, y) can be obtained by successive application of 1D fourier transform or its inverse.

n-1

F(u, v) =1/N ∑ F(x, v) e –j2πux/N

x=0

Where

n-1

F(x, v)=N[1/N ∑ f(x, y) e –j2πvy/N

y=0

30. What is meant by convolution?The convolution of 2 functions is defined by f(x)*g(x) = f(α)

.g(x- α) dα

where α is the dummy variable

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31. State convolution theorem for 1D

If f(x) has a fourier transform F(u) and g(x) has a fourier transform G(u) then f(x)*g(x) has a fourier transform F(u).G(u).

Convolution in x domain can be obtained by taking the inverse fourier transform of the product F(u).G(u).

Convolution in frequency domain reduces the multiplication in the x domain

F(x).g(x) F(u)* G(u)

These 2 results are referred to the convolution theorem.

32. What is wrap around error?

The individual periods of the convolution will overlap and referred to as wrap around error

33. Give the formula for correlation of 1D continuous function.The correlation of 2 continuous functions f(x) and g(x) is defined by f(x) o g(x) = f*(α )

g(x+α ) dα

34. Specify the properties of forward transformation kernel?

The forward transformation kernel is said to be separable if g(x, y, u, v)

g(x, y, u, v) = g1(x, u).g2(y, v)

The forward transformation kernel is symmetric if g1 is functionally equal to g2 g(x, y, u, v) = g1(x, u). g1(y,v)

35. Define fast Walsh transform.

The Walsh transform is defined by

n-1 x-1

w(u) = 1/N ∑ f(x) π (-1) bi(x).bn-1-i (u)

x=0 i=0

36..Give the relation for 1-D DCT.

The 1-D DCT is, N-1

C(u)=α(u)∑ f(x) cos[((2x+1)uп)/2N] where u=0,1,2,….N-1

X=0

N-1

Inverse f(x)= ∑ α(u) c(u) cos[((2x+1) uп)/2N] where x=0,1,2,…N-1

37.Define Haar transform.

The Haar transform can be expressed in matrix form as, T=HFH

Where F = N X N image matrix

H = N X N transformation matrix

T = resulting N X N transform.

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38.Define K-L transform.

Consider a set of n or multi-dimensional discrete signal represented as column vector x1,x2,…xn each having M elements,

X1

X2

X= .

. Xn

The mean vector is defined as Mx=Ex

Where Ex is the expected value of x. M

For M vector samples mean vector is Mx=1/M ∑ Xk

K=1

T The co-variant matrix is, Cx=E(X-Mx)(X-Mx)

Where T-vector transposition X->N-D vector Cx->nxn matrix. MT For M samples, Cx=1/M ∑ (xk-

Mx)(xk-Mx).

K=1

K-L Transform Y= A(X- MX)

Part-B

1. Explain the steps involved in digital image processing.

# Image acquisition

# Preprocessing

# Segmentation

# Representation and Description

# Recognition and Interpretat

2. Describe the elements of visual perception.

# Cornea and Sclera

# Choroid – Iris diaphragm and Ciliary body

# Retina- Cones and Rods

3.Write short notes on sampling and quantization.

# Sampling

# Quantization

# Representing Digital Images

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4. Describe the functions of elements of digital image processing system with a diagram.

# Acquisition

# Storage

# Processing

# Communication

# Display

5.Explain the basic relationships between pixels?

# Neighbors of a pixel

# Connectivity, Adjacency, Path

# Distance Measure

# Arithmetic and Logic Operations

6.Explain the properties of 2D Fourier Transform.

# Separability

# Translation

# Periodicity and Conjugate Symmetry

# Rotation

# Distribution and Scaling

# Average Value

# Laplacian

# Convolution and correlation

# Sampling

7. ( i )Explain convolution property in 2D fourier transform.

* 1DContinuous

* 1D Discrete

* 1D convolution theorem

* 2D continuous

* 2D Discrete

* 2D convolution theorem(ii) Find F (u) and |F (u)|

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8. Explain Fast Fourier Transform (FFT) in detail.

# FFT Algorithm

# FFT Implementation

9.Explain Hadamard transformation in detail.

# 1D DHT

# 1D Inverse DHT

# 2D DHT

# 2D Inverse DHT

10.Explain Haar transform in detail.

# Def P= 2P

+q-1

# Find h k (z)

11.Explain K-L transform in detail.

Consider a set of n or multi-dimensional discrete signal represented as column

vector x1,x2,…xn each having M elements,

X1

X2

X= .

. Xn

The mean vector is defined as Mx=Ex

Where Ex is the expected value of x. M

For M vector samples mean vector is Mx=1/M ∑ Xk

K=1T The co-variant matrix is,

Cx=E(X-Mx)(X-Mx)

M T

For M samples, Cx=1/M ∑ (xk-Mx)(xk-Mx).

K=1

K-L Transform Y= A (X- MX)

UNIT II


1. Specify the objective of image enhancement technique.

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Ans: The objective of enhancement technique is to process an image so that the result is more suitable than the original image for a particular application.

2. Explain the 2 categories of image enhancement.

i) spatial domain refers to image plane itself & approaches in this category are based on direct manipulation of picture image.

ii) Frequency domain methods based on modifying the image by fourier transform.

3. What is contrast stretching?

Contrast stretching reduces an image of higher contrast than the original by darkening

the levels below m and brightening the levels above m in the image.

4. What is grey level slicing?

Highlighting a specific range of grey levels in an image often is desired. Applications include enhancing features such as masses of water in satellite imagery and enhancing flaws in x-ray images.

5. Define image subtraction.

The difference between 2 images f(x,y) and h(x,y) expressed as,

g(x,y)=f(x,y)-h(x,y)

is obtained by computing the difference between all pairs of corresponding pixels from f and h.

6. What is the purpose of image averaging?

An important application of image averagingis in the field of astronomy, where

imaging with very low light levels is routine, causing sensor noise frequently to render single images virtually useless for analysis.

7. What is meant by masking?

Mask is the small 2-D array in which the values of mask co-efficient determines the

nature of process.

The enhancement technique based on this type of approach is referred to as mask processing.

8. Give the formula for negative and log transformation.

Negative: S=L-1-r

Log: S=clog(1+r) Where c-constant and r≥0

9. What is meant by bit plane slicing?

Instead of highlighting gray level ranges, highlighting the contribution made to total

image appearance by specific bits might be desired. Suppose that each pixel in an image is represented by 8 bits. Imagine that the image is composed of eight 1-bit planes, ranging from bit plane 0 for LSB to bit plane-7 for MSB.

80

-1 -1 -1

-1 A+8 -1

-1 -1 -1


10. Define histogram.

The histogram of a digital image with gray levels in the range [0,L-1] is a discrete

function h(rk)=nk.

rk-kth gray level

11. What is meant by histogram equalization?

k k

Sk= T(rk) = ∑ Pr(rj) = ∑ nj/n where k=0,1,2,….L-1 j=0 j=0

This transformation is called histogram equalization.

12. Differentiate linear spatial filter and non-linear spatial filter.

s.no. Linear spatial filter Non-linear spatial filter

1.

2.

Response is a sum of products of the filter co-efficient.

R = w(-1,-1) f(x-1,y-1) + w(-1,0) f(x-1,y) + … + w(0,0) f(x,y) + … + w(1,0) f(x+1,y) + w(1,1) f(x+1,y+1).

They do not explicitly use coefficients in the sum-of-products.

R = w1z1 + w2z2 + … +w9z9

9

= ∑ wizi i=1

13. Give the mask used for high boost filtering.

0 -1 0

-1 A+4 -1

0 -1 0

14. What is meant by laplacian filter?

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The laplacian for a function f(x,y) of 2 variables is defined as,

2 2 2 2 2

f = ∂ f / ∂ x + ∂ f / ∂ y

15. Write the steps involved in frequency domain filtering.

x+y

1. Multiply the input image by (-1) to center the transform.

2. Compute F(u,v), the DFT of the image from (1).

3. Multiply F(u,v) by a filter function H(u,v).

4. Compute the inverse DFT of the result in (3).

5. Obtain the real part of the result in (4). x+y

6. Multiply the result in (5) by (-1)

16. Give the formula for transform function of a Butterworth low pass filter. The transfer function of a Butterworth low pass filter of order n and with cut off frequency at a distance D0 from the origin is,

2n

H(u,v) = 1 / 1 + [ D(u,v) / D0 ]

2 2 1/2

Where D(u,v) = [(u – M/2) + (v-N/2) ]

Part-B

1.Explain the types of gray level transformation used for image enhancement.

# Linear (Negative and Identity)

# Logarithmic( Log and Inverse Log)

# Power_law (nth root and nth power)

# Piecewise_linear (Constrast Stretching, Gray level Slicing, Bit plane Slicing)

2. What is histogram? Explain histogram equalization.

# P(rk) = nk/n

# Ps(s) = 1 means histogram is arranged uniformly.

3. Explain spatial filtering in image enhancement.

# Basics

# Smoothing filters

# Sharpening filters

4. Explain image enhancement in the frequency domain.

# Smoothing filters

# Sharpening filters

# Homomorphic filtering

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5.Explain Homomorphic filtering in detail.

# f(x, y) = i(x, y) . r(x, y)

# Calculate the enhanced image g(x,y)

UNIT III


1.What is meant by Image Restoration?

Restoration attempts to reconstruct or recover an image that has been degraded by

using a clear knowledge of the degrading phenomenon.

2.What are the two properties in Linear Operator?

Additivity

Homogenity

3.Explain additivity property in Linear Operator?

H[f1(x,y)+f2(x,y)]=H[f1(x,y)]+H[f2(x,y)]

The additive property says that if H is the linear operator,the response to a

sum of two is equal to the sum of the two responses.

4.Explain homogenity property in Linear Operator?

H[k1f1(x,y)]=k1 H[f1(x,y)]

The homogeneity property says that,the response to a constant multiple of

any input is equal to the response to that input multiplied by the same constant.

5.Give the relation for degradation model for continuous function?

g(x,y) =-∞∫∞

∫f(α,β)§(x-α,y-β).dαdβ+η(x,y)

6.what is concept algebraic approach?

The concept of algebraic approach is to estimate the original image which

minimizes a predefined criterion of performances.

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7.What are the two methods of algebraic approach?

o Unconstraint restoration approacho Constraint restoration approach

8.What is meant by Noise probability density function?

The spatial noise descriptor is the statistical behavior of gray level values in the

noise component of the model.

9.what are the types of noise models?

> Guassian noise

> Rayleigh noise

> Erlang noise

> Exponential noise

> Uniform noise

> Impulse noise

10.Give the relation for guassian noise?

Guassian noise:

The PDF guassian random variable Z is given by

P(Z)=e-(Z-µ)2/2σ2

/√2πσ

Z->Gray level value

σ->standard deviation

σ2

->varianze of Z

µ->mean of the graylevel value Z

11. .Give the relation for rayleigh noise?

Rayleigh noise:

The PDF is

P(Z)= 2(z-a)e-(z—a)2/b

/b for Z>=a

0 for Z<a

mean µ=a+√πb/4 standard deviation σ

2=b(4-π)/4

12.Give the relation for Gamma noise?

Gamma noise:

The PDF is

P(Z)=ab

zb-1

ae-az

/(b-1) for Z>=0

0 for Z<0 mean µ=b/a

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standard deviation σ2

=b/a2

13.Give the relation for Exponential noise?

Exponential noise

The PDF is

P(Z)= ae-az

Z>=0

0 Z<0 mean µ=1/a standard deviation σ

2=1/a

2

14.Give the relation for Uniform noise?

Uniform noise:

The PDF is

P(Z)=1/(b-a) if a<=Z<=b0 otherwise mean

µ=a+b/2 standard

deviation σ2

=(b-a)2

/12

15.Give the relation for Impulse noise?

Impulse noise:

The PDF is

P(Z) =Pa for z=a

Pb for z=b

0 otherwise

116.What is meant by inverse filtering?

Inverse filtering is the process of recovering the input of the system from its

output.

17.What is pseudo inverse filter?

It is the stabilized version of the inverse filter.For a linear shift invariant system

with frequency response H(u,v) the pseudo inverse filter is defined as

H-(u,v)=1/(H(u,v) H=/0

0 H=0

18.What is meant by least mean square filter?

The limitation of inverse and pseudo inverse filter is very sensitive noise.The

wiener filtering is a method of restoring images in the presence of blurr as well as noise.

19.Give the equation for singular value decomposition of an image?

U= m=1∑rψ√λm φ

T

This equation is called as singular value decomposition of an image.

85


20.Write the properties of Singular value Decomposition(SVD)?

• The SVD transform varies drastically from image to image.

• The SVD transform gives best energy packing efficiency for any given

image.

• The SVD transform is useful in the design of filters finding least square,minimum solution of linear equation and finding rank of large matrices.

21.What is meant by blind image restoration?

An information about the degradation must be extracted from the observed image

either explicitly or implicitly.This task is called as blind image restoration.

22.What are the two approaches for blind image restoration?

> Direct measurement

> Indirect estimation

23. What is meant by Direct measurement?

In direct measurement the blurr impulse response and noise levels are first

estimated from an observed image.where this parameter are utilized in the restoration.

24.What is blur impulse response and noise levels?Blur impulse response: This parameter is measured by isolating an image of a suspected object

within a picture.

Noise levels: The noise of an observed image can be estimated by measuring the image covariance over a region of constant background luminence.

25. What is meant by indirect estimation?

Indirect estimation method employ temporal or spatial averaging to either obtain a

restoration or to obtain key elements of an image restoration algorithm.

Part-B

1. Explain the algebra approach in image restoration.

# Unconstrained

# Constrained

2. What is the use of wiener filter in image restoration. Explain.

# Calculate f^

# Calculate F^(u, v)

3. What is meant by Inverse filtering? Explain.

86


# Recovering i/p from its o/p

# Calculate f^(x, y)

4. Explain singular value decomposition and specify its properties.

# U= m=1∑rψ√λm φ

T

This equation is called as singular value decomposition of an image.

# Properties

•The SVD transform varies drastically from image to image.

•The SVD transform gives best energy packing efficiency for any given

image.

•The SVD transform is useful in the design of filters finding least square,minimum solution of linear equation and finding rank of large matrices.

5. Explain image degradation model /restoration process in detail.

# Image degradation model /restoration process diagram

# Degradation model for Continuous function

# Degradation model for Discrete function – 1_D and 2_D

6. What are the two approaches for blind image restoration? Explain in detail.

> Direct measurement

> Indirect estimation

UNIT IV


1. What is image compression?

Image compression refers to the process of redundancy amount of data required to

represent the given quantity of information for digital image. The basis of reduction process is removal of redundant data.

2. Define is coding redundancy?

If the gray level of an image is coded in a way that uses more code words than

necessary to represent each gray level, then the resulting image is said to contain coding redundancy.

3. Define interpixel redundancy?

The value of any given pixel can be predicted from the values of its neighbors.

The information carried by is small. Therefore the visual contribution of a single pixel to an image is redundant. Otherwise called as spatial redundant geometric redundant or interpixel redundant.

87


Eg: Run length coding

4. Define psycho visual redundancy?

In normal visual processing certain information has less importance than other

information. So this information is said to be psycho visual redundant.

5. Define encoder

Source encoder is responsible for removing the coding and interpixel redundancy

and psycho visual redundancy.

There are two components A) Source Encoder B) Channel Encoder

6. Define source encoder

Source encoder performs three operations

1) Mapper-this transforms the input data into non-visual format. It reduces the interpixel redundancy.

2) Quantizer- It reduces the psycho visual redundancy of the input images .This step is omitted if the system is error free.

3) Symbol encoder- This reduces the coding redundancy .This is the final stage of encoding process.

7. Define channel encoder

The channel encoder reduces reduces the impact of the channel noise by inserting

redundant bits into the source encoded data.

Eg: Hamming code

8. What are the types of decoder?

Source decoder- has two components

a) Symbol decoder- This performs inverse operation of symbol encoder. b) Inverse mapping- This performs inverse operation of mapper.

Channel decoder-this is omitted if the system is error free.

9. What are the operations performed by error free compression?

1) Devising an alternative representation of the image in which its interpixel

redundant are reduced.

2) Coding the representation to eliminate coding redundancy

10. What is Variable Length Coding?

Variable Length Coding is the simplest approach to error free compression. It

reduces only the coding redundancy. It assigns the shortest possible codeword to the most probable gray levels.

11. Define Huffman coding

88


• Huffman coding is a popular technique for removing coding redundancy.

• When coding the symbols of an information source the Huffman code

yields the smallest possible number of code words, code symbols per

source symbol.

12. Define Block code

Each source symbol is mapped into fixed sequence of code symbols or code

words. So it is called as block code.

13. Define instantaneous code

A code word that is not a prefix of any other code word is called instantaneous or

prefix codeword.

14. Define uniquely decodable code

A code word that is not a combination of any other codeword is said to be

uniquely decodable code.

15. Define B2 code

Each code word is made up of continuation bit c and information bit which are

binary numbers. This is called B2 code or B code. This is called B2 code because two information bits are used for continuation bits

16. Define the procedure for Huffman shift

List all the source symbols along with its probabilities in descending order.

Divide the total number of symbols into block of equal size. Sum the probabilities of all the source symbols outside the reference block. Now apply the procedure for reference block, including the prefix source symbol. The code words for the remaining symbols can be constructed by means of one or more prefix code followed by the reference block as in the case of binary shift code.

17. Define arithmetic coding

In arithmetic coding one to one corresponds between source symbols and code

word doesn’t exist where as the single arithmetic code word assigned for a sequence of source symbols. A code word defines an interval of number between 0 and 1.

18. What is bit plane Decomposition?

An effective technique for reducing an image’s interpixel redundancies is to

process the image’s bit plane individually. This technique is based on the concept of decomposing multilevel images into a series of binary images and compressing each binary image via one of several well-known binary compression methods.

19. What are three categories of constant area coding?

The three categories of constant area coding are89


• All white

• All black

• Mixed intensity.

The most probable or frequency occurring is assign a 1 bit code ‘0’, other two

categories area assigned as 2 bit code ‘10’ and ‘11’

20. Draw the block diagram of transform coding system

Input image Wavelet transform Quantizer Symbol encoder

Compressed image

Compressed image

Symbol decoder

Inverse wavelet transform

Decompressed image

90

21. How effectiveness of quantization can be improved?• Introducing an enlarged quantization interval around zero, called a dead zero.• Adapting the size of the quantization intervals from scale to scale. In either

case, the selected quantization intervals must be transmitted to the decoder with the encoded image bit stream.

22. What are the coding systems in JPEG?

1. A lossy baseline coding system, which is based on the DCT and is

adequate for most compression application.

2. An extended coding system for greater compression, higher precision or progressive reconstruction applications.

3. a lossless independent coding system for reversible compression.

23. Define I-frame

I-frame is Intraframe or Independent frame. An I-frame is compressed

independently of all frames. It resembles a JPEG encoded image. It is the reference point for the motion estimation needed to generate subsequent P and P-frame.

24. Define P-frame

P-frame is called predictive frame. A P-frame is the compressed difference

between the current frame and a prediction of it based on the previous I or P-frame

25. Define B-frame

B-frame is the bidirectional frame. A B-frame is the compressed difference

between the current frame and a prediction of it based on the previous I or P-frame or

next P-frame. Accordingly the decoder must have access to both past and future reference frames.

Part-B

1. What is data redundancy? Explain three basic data redundancy?

Definition of data redundancy

The 3 basic data redundancy are

> Coding redundancy

> Interpixel redundancy

> Psycho visual redundancy

2. What is image compression? Explain any four variable length coding compression schemes.

• Definition of image compression

• Variable Length Coding

* Huffman coding

* B2 Code

* Huffman shift

* Huffman Truncated

* Binary Shift

*Arithmetic coding

3.Explain about Image compression model?

• The source Encoder and Decoder

• The channel Encoder and Decoder

4. Explain about Error free Compression?

a. Variable Length coding

i. Huffman coding

ii. Arithmetic coding b. LZW coding

c. Bit Plane coding

d. Lossless Predictive coding

5. Explain about Lossy compression?

1 Lossy predictive coding

1 Transform coding

1 Wavelet coding

6. Explain the schematics of image compression standard JPEG.

• Lossy baseline coding system

• Extended coding system

• Lossless Independent coding system

7. Explain about Image compression standards?

• Binary Image compression standards

• Continuous tone still Image compression standards

• Video compression standards

UNIT V


1.What is segmentation?

Segmentation subdivides on image in to its constitute regions or objects. The level to

which the subdivides is carried depends on the problem being solved That is segmentation should when the objects of interest in application have been isolated.

2.What is edge?

An edge isa set of connected pixels that lie on the boundary between two regions edges

are more closely modeled as having a ramplike profile. The slope of the ramp is inversely proportional to the degree of blurring in the edge.

3.Give the properties of the second derivative around an edge?

* The sign of the second derivative can be used to determine whether an edge pixel lies

on the dark or light side of an edge.

* It produces two values for every edge in an image.

* An imaginary straightline joining the extreme positive and negative values of the second derivative would cross zero near the midpoint of the edge.

4.Define Gradient Operator?

First order derivatives of a digital image are based on various approximation of

the 2-D gradient. The gradient of an image f(x,y) at location(x,y) is defined as the vector

Magnitude of the vector is

∆f=mag( ∆f )=[Gx2

+ Gy2

]1/2

∞(x,y)=tan-1

(Gy/Gx)

∞(x,y) is the direction angle of vector ∆f

5.What is meant by object point and background point?

To execute the objects from the background is to select a threshold T that separate these

modes. Then any point (x,y) for which f(x,y)>T is called an object point. Otherwise the point is called background point.

6.What is global, Local and dynamic or adaptive threshold?

When Threshold T depends only on f(x,y) then the threshold is called global . If T

depends both on f(x,y) and p(x,y) is called local. If T depends on the spatial coordinates x and y the threshold is called dynamic or adaptive where f(x,y) is the original image.

7.Define region growing?

Region growing is a procedure that groups pixels or subregions in to layer regions based

on predefined criteria. The basic approach is to start with a set of seed points and from there grow regions by appending to each seed these neighbouring pixels that have properties similar to the seed.

8.Specify the msteps involved in splitting and merging?

Split into 4 disjoint quadrants any region Ri for which P(Ri)=FALSE.

Merge any adjacent regions Rj and Rk for which P(RjURk)=TRUE. Stop when no further merging or splitting is positive.

9.What is meant by markers?

An approach used to control over segmentation is based on markers.

marker is a connected component belonging to an image. We have internal markers, associated with objects of interest and external markers associated with background.

10.What are the 2 principles steps involved in marker selection?

The two steps are

1. Preprocessing

2. Definition of a set of criteria that markers must satisfy.

11.Define chain codes?

Chain codes are used to represent a boundary by a connected sequence of

straight line segment of specified length and direction. Typically this representation is

based on 4 or 8 connectivity of the segments . The direction of each segment is coded by using a numbering scheme.

12.What are the demerits of chain code?

* The resulting chain code tends to be quite long.

* Any small disturbance along the boundary due to noise cause changes in the code that may not be related to the shape of the boundary.

13.What is thinning or skeletonizing algorithm?

An important approach to represent the structural shape of a plane region is to

reduce it to a graph. This reduction may be accomplished by obtaining the skeletonizing algorithm. It play a central role in a broad range of problems in image processing, ranging from automated inspection of printed circuit boards to counting of asbestos fibres in air filter.

14.Specify the various image representation approaches

• Chain codes

• Polygonal approximation

• Boundary segments

15.What is polygonal approximation method ?

Polygonal approximation is a image representation approach in which a digital

boundary can be approximated with arbitary accuracy by a polygon.For a closed curve the approximation is exact when the number of segments in polygon is equal to the number of points in the boundary so that each pair of adjacent points defines a segment in the polygon.

16. Specify the various polygonal approximation methods

• Minimum perimeter polygons

• Merging techniques

• Splitting techniques

17.Name few boundary descriptors

• Simple descriptors

• Shape numbers

• Fourier descriptors

18.Give the formula for diameter of boundary

The diameter of a boundary B is defined as

Diam(B)=max[D(pi,pj)]

i,j

D-distance measure

pi,pj-points on the boundary

19. Define length of a boundary.

The length of a boundary is the number of pixels along a boundary.Eg.for a chain

coded curve with unit spacing in both directions the number of vertical and horizontal components plus √2 times the number of diagonal components gives its exact length.

20. Define eccentricity and curvature of boundary

Eccentricity of boundary is the ratio of the major axis to minor axis.

Curvature is the rate of change of slope.

21. Define shape numbers

Shape number is defined as the first difference of smallest magnitude. The order n of

a shape number is the number of digits in its representation.

22.Describe Fourier descriptors

Fourier descriptor of a boundary can be defined asK-1 a(u)=1/K∑s(k)e

-j2Πuk/K

k=0

for u=0,1,2……K-1.The complex coefficients a(u) are called Fourier descriptor of a boundary.

The inverse Fourier descriptor is

K-1

s(k)= ∑ a(u)ej2Πuk/K

u=0

for k=0,1,2,……K-1

23. Give the Fourier descriptors for the following transformations

(1)Identity (2)Rotation (3)Translation (4)Scaling (5)Starting point

(1)Identity – a(u) (2)Rotation -ar(u)= a(u)e

jθ

(3) Translation-at(u)=a(u)+∆xyδ(u) (4)Scaling-as(u)=αa(u)

(5)Starting point-ap(u)=a(u)e-j2Πuk /K

24.Specify the types of regional descriptors


• Texture

25.Name few measures used as simple descriptors in region descriptors

• Area

• Perimeter

• Compactness

• Mean and median of gray levels

• Minimum and maximum of gray levels

• Number of pixels with values above and below mean

26.Define compactness

Compactness of a region is defined as (perimeter)^2/area.It is a

dimensionless quantity and is insensitive to uniform scale changes.

27.Describe texture

Texture is one of the regional descriptors.It provides measures of

properties such as smoothness,coarseness and regularity. There are 3 approaches used to describe texture of a region.

They are:

• Statistical

• Structural

• Spectral

28.Describe statistical approach

Statistical approaches describe smooth,coarse,grainy characteristics of

texture.This is the simplest one compared to others.It describes texture using statistical moments of the gray-level histogram of an image or region.

29.Define gray-level co-occurrence matrix.

A matrix C is formed by dividing every element of A by n(A is a k x k

matrix and n is the total number of point pairs in the image satisfying P(position operator). The matrix C is called gray-level co-occurrence matrix if C depends on P,the presence of given texture patterns may be detected by choosing an appropriate position operator.

30.Explain structural and spectral approach

Structural approach deals with the arrangement of image primitives such as

description of texture based on regularly spaced parallel lines.

Spectral approach is based on properties of the Fourier spectrum and are primarily to detect global periodicity in an image by identifying high energy,narrow peaks in spectrum.There are 3 features of Fourier spectrum that are useful for texture description. They are:

• Prominent peaks in spectrum gives the principal direction of texture patterns.

• The location of peaks in frequency plane gives fundamental spatial period of

patterns.• Eliminating any periodic components by our filtering leaves non- periodic image

elements.

Part-B

1.What is image segmentation. Explain in detail.

• Definition - image segmentation

• Discontinity – Point, Line, Edge

• Similarity – Thresholding, Region Growing, Splitting and

merging

2.Explain Edge Detection in details?

* Basic formation.

* Gradient Operators

* Laplacian Operators

3.Define Thresholding and explain the various methods of thresholding in detail?

• Foundation

• The role of illumination

• Basic adaptive thresholding

• Basic adaptive thresholding

• Optimal global & adaptive thresholding.

4.Discuss about region based image segmentation techniques. Compare threshold region based techniques.

* Region Growing

* Region splitting and merging

* Comparison

5.Define and explain the various representation approaches?

• chain codes

• Polygon approximations

• Signature

• Boundary segments

• Skeletons.

6.Explain Boundary descriptors.

• Simple descriptors.

• Fourier descriptors.

7. Explain regional descriptors


• Texture

i. Statistical approach

ii. Structural approach iii. Spectral app

MEDICAL ELECTRONICS

Medical electronicsUNIT I


1.Explain the Cell Structure

The basic living unit of the body is a cell. Each organ in our body is an aggregate of many different cells held together by intercellular supporting structures. Each type of cell is meant for performing one particular function. Each cell consists of a centrally located nucleus, also called cell core, surrounded by cytoplasm. The nucleus is separated from the cytoplasm is separated from the surrounding fluids by a cell membrane. The different substances that make up the cell one collectively called protoplasm which is mainly composed of water ,electrolytes ,proteins, carbohydrates and lipids.

2. What are the applications of piezo electric sensors? 1) In cardiology 2) In phono cardiography 3) In blood pressure measurement 4) In measuring physiological accelerations

3. What are the different thermal sensors? 1) Thermo couples 2) Thermistors 3) Radiation sensors 4) Fiber optic detectors

3. Give the different types of inductive sensors. 1) Self inductance type 2) Mutual inductance type 3) Differential transformer type (LVDT)

4. What are the advantages of LVDT?1) Wide range of linearity2) Change of phase by 180 Deg When the core passes through the center position3) Full-scale displacement is 0.1- 250mm.4) Sensitivity is 0.5- 2 mV.

5. What are the limitations of capacitive sensor? Inadequate for measuring most physiological variables because of their

low frequency components.

6. What is the principle of piezo electric sensors?

The piezo electric materials generate an electric potential when mechanically strained. Conversely, an electric potential can cause physical deformation of the materials

7.Define Resting Potential

Certain type of cells within the body ,such as nerve and muscle cell are encased in a semi permeable membrane that permits same substances to pass through the membrane, while others are kept out .Surrounding the cells of the body, are the body fluids which are conductive solutions of charge ions. The principal ions are sodium(na+), Potassium(e+) and chloride(cl-) the membrane of the excitable cells readily permits entry of potassium and chloride ions but blocks the entry of sodium ions , since the various ions seek balance between inside the cell and outside. Equilibrium is reached with the potential difference

MEDICAL ELECTRONICS

across the membrane –ive on the inside and +ive on the outside of the cell. This membrane potential is called the Resting Potential of the cell.

8.Define Action Potential.

When a section of cell membrane is excited by a flow of ionic current or same form of externally applied voltage the membrane changes its permeability and begins to allow to some of the sodium ions to enter. This movement of sodium ions into the cell results in an ionic current flow that further reduces the barrier of membrane to sodium ion rush into the cell to try to reach to balance with the ions outside. At the same time potassium ions which were higher in the concentration inside the cell during the resting stage try to leave the cell, but are unable to move as rapidly as sodium ions. As a result the cell has a slightly positive potential on the due to imbalance of potassium ions. This +ive potential is called action potential and this is approximately +20mv .A cell in the action potential stage is said to be depolarized. The process of changing from resting stage to action potential stage is called depolarization.

9. Explain Bioelectric Potential

Bioelectric potential are generated at a cellular level. that is each cell is a minute voltage generator .because positive and negative ions tend to concentrate unequally inside and outside the cell wall, a potential difference is established and the cell becomes a tiny biological battery. In the normal resting state of the cell it interior is negative with respect to the outside when the cells “fires” however ,the outside of the cell becomes momentarily negative with respect to the interior .A short time later, the cell regains the normal state in which the inside is again negative with respect to outside. This “discharging” and “recharging” of the cell known as depolarization and depolarization respectively.

10. Name the factors that are considered in the design of biomedical instrument system.1.Range2.Sensitivity3.Linearity4.Frequency Response5.Accuracy6.Stability7.Isolation8.Simplicity9.Signal to noise ratio.

11. Name the physiological systems of the body.1. Bio chemical System2. Cardio vascular System3. Regulated System4. Nervous System

12..State the principal of the sodium pump

Once the rush of sodium ions through the cell membrane has stopped that is a new stage of equilibrium is reached, the ionic currents that lowered the barrier to sodium ions are no longer present and the membrane comes back into its original selectively permeable condition, where in the passage of sodium ions from the outside to inside of the cell is again blocked. This take a long time for the resting potential to develop again .But by the active process called sodium pump, the sodium ions are quickly transported outside of the cell and the cell again becomes polarized and assumes its resting potential. This process is called depolarization.

MEDICAL ELECTRONICS

13..Name the different types of electrodes:

1.Micro Electrode 2.Surface Electrode 3.Depth and needle Electrode A) Metallic B) Non –Metallic

14.What are the requirements of physiological signal amplifier or biomedical pre amplifier?a)The voltage gain should be more than 100 db.b)It should have low frequency response.c)There is no drift in the amplifier.d)The output impedance of the amplifier should be very small.

15.What are the different modes of operation of differential amplifier? a)single ended mode b)differential mode c)common mode

16.What is single ended mode?

When either v1 or v2 is equal to zero ,the operation of the differential amplifier is known as single ended mode of operation.

17.What is differential mode?

The two input signals are equal but have opposite polarity at every instant of time. Vo=Rf/Ri(V2-V1) In this case ,the input signals are called differential mode signals.

18.What is common mode signal?

The input voltages appearing at the input terminals 1 and 2 are identical both in amplitude and phase at every instant of time and the circuit is said to be in common mode.

V1=V2=Vcm , Vo=0.

19.What is CMRR in a differential amplifier?

It is the ratio of the amplification of the differential voltage ti the amplification of the common mode voltage. CMRR=Ad/Ac. CMRR in db=20 log10 CMRR.

20.What is noise figure?

It is defined as the ratio of the signal to noise ratio at the input to the signal to noise ratio at the output.

21.What are the advantages of the pre amplifier or instrumentation amplifier?a)high stability c)high CMRRb)higher fidelity. d)high input impedance with the required gain

22.What is chopper amplifier?

The chopper amplifier is used convert the dc or low frequency signal into a high frequency signal. Then this modulated high frequency signal is amplified by conventional ac amplifier. Then this is demodulated and filtered to get low frequency or dc signal.

MEDICAL ELECTRONICS

23.What are the types of chopper amplifier? a)mechanical chopper amplifier. b)non mechanical chopper amplifier.

24. Define Neuron.

Neurons (also known as neurons, nerve cells and nerve fibers) are electrically excitable cells in the nervous system that function to process and transmit information. Neurons are typically composed of a soma, or cell body, a dendrite tree and an axon. The majority of vertebrate neurons receive input on the cell body and dendrite tree, and transmit output via the axon. Neurons communicate via chemical and electrical synapses, in a process known as synaptic transmission

25. Draw the structure of the Nerve Cell

6 .Draw the Wave form of the resting and action potential.

PART - B 1) Draw the structure of cell & explain the various compositions with theirfunctions.Structure of Cell - ExplanationRef : Biomedical Instrumentation - Dr. M. Arumugam2) Define resting potential & Action potential. Explain how these potentials are generated in human body.Resting & Action Potential generation Polarization & Depolarization of cellSodium pump –descriptionRef : Biomedical Instrumentation & Measurements - Leslie CromwellFred J. Weibell &Erich A. Pfeiffer

MEDICAL ELECTRONICS

3) Explain in detail the different types of Electrodes used for biomedicalapplications.Microelectrodes Depth & Needle electrodes Surface electrodes Chemical electrodesRef : Biomedical Instrumentation - Dr. M. Arumugam

4) Describe the different sensors used in biomedicine.Force transducers , Transducers for Displacement, Velocity, AccelerationPressure transducers , Flow transducers Transducers for digital outputRef : Biomedical Instrumentation & Measurements - Leslie CromwellFred J. Weibell &Erich A. Pfeiffer5)Explain in detail the electrical safety & grounding & isolation techniques.

Physiological effects of Electrical current Shock hazards from electrical equipment Methods of accident prevention

Ref : Biomedical Instrumentation & Measurements - Leslie CromwellFred J. Weibell &Erich A. Pfeiffer

UNIT-II


1.What is Electrocardiography?

It deals with the study of the electrical activity of the heart muscles. The potentials originated in the individual fibres of heart muscle are added to produce the ECG waveform

2.What are the various parts of generalized instrumentation system .

1..Primary sensing element

2.Variable conversion element

3. Signal processing unit

4.Output display

5.Control & feedback element

3 Give the classifications of biomedical instruments.

i) According to the quantity that is sensed, pressure, flow or temperature sensing devices.

ii) According to the principle of transduction used, resistive, inductive, capacitive, ultrasonic or electrochemical devices.iii) According to the measurement techniques, cardio vascular, pulmonary, nervous & endocrine systems.iv) According to the clinical medical specialties, pediatrics, obstetrics, cardiology or radiology.

4. What are the different types of ECG lead configurations? Bipolar limb leads Augmented unipolar limb leads Chest leads Frank lead system

MEDICAL ELECTRONICS

5. Define the Einthoven Triangle

The closed path RA to LA to LL and back to RA is called Einthoven triangle. According to Einthoven, in a frontal plane of the body, the cardiac electric field vector is a two dimensional one.

6. What are the important parts of ECG recorder?

Patient cable and defibrillator protection circuit. Lead selector switch , Power switch

Calibrator ,Bio- amplifier , Auxiliary amplifier

Isolated power supply and Output unit

7. Draw the Standard ECG.

8. Draw the ECG curve for Bundle block

9. What is Electroencephalography?

It deals with the recording and study of electrical activity of the brain. By means of electrodes attached to the skull of a patient, brain waves can be picked up and recorded.

MEDICAL ELECTRONICS

10. What is Electromyography?

It is the science of interpreting and recording the electrical activity of the muscles action potentials. Meanwhile, the recording of the peripheral nerve’s action potential is called electroneurography.

11. Draw the block diagram of EMG recording setup.

12. What is Electrooculography?

It deals with the recording of the corneal- retinal potentials associated with eye movements.

13. What is Electroretinography?

It deals with the recording and interpreting of the electrical activity of the eye. If the illumination of the retina is changed, the potential changes slightly in a complex manner. The recording of these changes is called Electroretinograph.

14. List the brain waves and their frequency.

Alpha- 8 to 13Hz, Beta-13 to 30 Hz , Theta- 4 to 8 Hz, Delta- 0.5 to 4 Hz.

15. Define latency.

It is defined as the elapsed time between the simulating impulse and the muscle’s action potential.

16. What are the different sounds made by the heart?

Valve closure sounds, Ventricular filling sounds, Valve opening sounds, Extra cardiac sounds

17. Name the parts of the heart conduction system.

Sino atrial node, Atrio ventricular node, Bundle of His , Purkinje fibres.18. What is the colour coding of the different leads?

White –RA, Black- LA, Green- RL , Red- LL, Brown- Chest16. Mention any four specifications of the ordinary ECG recorder.

MEDICAL ELECTRONICS

Maximum sensitivity – 20 mm/mV, Input impedance –5 mega ohms, Output impedance -<100 ohms, CMRR- 10000:1.

PART - B

1) With neat diagram explain ECG?2) With neat diagram explain EEG?3) With neat diagram explain EMG?4) With neat diagram explain EOG?5) Explain how recorders are selected with high accuracy?6) Explain Different lead system for recording ECG.

In standard ECG recording there are 5 electrodes connected to the patient. Right arm, Left arm, Left leg, Right leg and chest. These electrodes are connected to the input of a differential amplifier through a lead selector switch.The recording obtained across different pairs of electrodes results in different waveform shapes and amplitudes; each lead conveys a certain amount of unique information. The ECG machine uses the patients right leg as common electrode and the lead selector connects proper limb or chest electrodes to the diff amplifier input. The bipolar limb leads are those designated lead I , lead II and lead III and form what is called Einthoven triangle.1.lead I : LA is connected to the amplifiers non inverting input, while RA is connected to the inverting terminal.2. Lead II: The LL is connected to the amplifiers NI input, while RA is connected to the inverting input.3. Lead III: the LL is connected to the NI terminal while LA is connected to theinverting input.Lead I: VI = FL – FR Lead II: VII = FF - FRLead III: VIII = FF – FL VI : the voltage of Lead IVII : the voltage of Lead II VII : the voltage of Lead IIIFL = potential at the left arm FR = potential at the left armFF = potential at the left armEinthoven's Triangle and LawEinthoven, the father of electrocardiography, visualized the three standard limb leads enclosing the heart in a triangle, often referred to as Einthoven's triangle Einthoven also found a relationship between the amplitude of the QRS complexes in each lead, such that lead I +lead III = lead II (Einthoven's law).The unipolar limb lead are also known as the augmented limb leads, examine thecomposite potential from all three leads simultaneously. In all augmented leads the signals from two limbs are summed in a resistor network and then applied to the amplifiers inverting input, while the signal from the remaining limb electrode is applied to the non inverting input.1. Lead aVR: RA is connected to the non inverting input, while LA and LL aresummed at the inverting terminal.2. Lead aVL: LA is connected to the non inverting input, while RA and LL aresummed at the inverting input.3. Lead aVF: LL is connected to the non inverting input , while RA and LA aresummed at the inverting input.The unipolar chest leads (V1 through V6) are measured with the signals from certain specified locations on the chest applied to the amplifiers non inverting input, while the RA, LA and LL signals are summed in a resistor network at the amplifiers inverting inputs.

MEDICAL ELECTRONICS

Unit III


1. What are the types of measurements of blood pressure? 1. Indirect or noninvasive method. 2. Direct or invasive method.2. How is the blood pressure measured in the indirect method?

The indirect method of measuring blood pressure involves the use of asphygmomanometer and a stethoscope. The sphygmomanometer consists of an inflatable pressure cuff and a mercury or aneroid manometer to measure the pressure in the cuff. The cuff is normally manually inflated, with a rubber bulb and deflated slowly through a needle valve.

3. Explain the principle of sphygmomanometer.

The sphygmomanometer works on the principle that when the cuff is placed on the upper arm and inflated, the arterial blood can flow past the cuff only when the arterial pressure exceeds the pressure in the cuff. Further more, when the cuff is inflated to a pressure that only occludes the brachial artery, turbulence is generated in the blood as it spurts through the tiny arterial opening during each systole. The sounds generated by this turbulence, Korotkoff sounds, can be heard through the stethoscope placed over the artery downstream from the cuff.

4. What are the methods involved in direct blood pressure measurement?

1. Auscultatory method 2. Palpatory method Auscultatory method locates the systolic and diastolic pressure valves by listening to the Korotkoff sound.

Palpatory method is an alternative method in which the physician identifies the flow of blood in the artery by feeling the pulse of the patient downstream from the cuff instead of listening for the Korotkoff sounds. In this method, systolic pressure can be easily measured. 5. What is meant by mean arterial pressure(MAP)?

A. Mean Arterial pressure is the weighted average of the systolic and diastolic pressure MAP falls about one- third of the way between the diastolic low and systolic peak. Formula for calculating MAP is,

MAP = 1/3 (systolic –diastolic) + diastolic

6. What are the methods involved in direct blood pressure measurement?

1. Percutaneous insertion 2. Catheterization(Vessel Cutdown) 3. Implantation of a transducer in a vessel or in the heart. 4. Other methods such as clamping a transducer on the intact artery have also been used. But they are not common.

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7. Explain the two ways involved in measurement of blood pressure with a catheter?

1. The first is to introduce a sterile saline solution into catheter so the fluid pressure is transmitted to a transducer outside the body a complete fluidpressure system is set up with provisions for checking against atmosphericpressure and for establishing a reference point. The frequency response ofthis system is a combination of the frequency response of the transducer andthe fluid column in the catheter.

2. In the second method, pressure measurements are obtained at the source. Here, the transducer is introduced into the catheter and pushed to the point at which the pressure is to be measured, or the transducer is mounted at the tip of the catheter. This device is called a catheter-tip blood pressuretransducer.

8. Discuss the technique involved in direct measurement?

1)A catheterization method involving the sensing of the blood pressure through a liquid column. In this method the transducer is external to the body and the blood pressure is transmitted through a saline solution column in a catheter to this transducer. 2) A catheterization method involving the placement of the transducer through the catheter at the actual size of measurement in the bloodstream or by mounting the transducer on the tip of the catheter. 3)Percutaneous methods in which the blood pressure is sensed in the vessel just under the skin by the use of a needle or catheter. 4)Implantation techniques in which the transducer is more permanently placed in the blood vessels or the heart by surgical methods.

9) What are the different types of blood flow meters?

1)Magnetic blood flow meter –Based on the principle of Magnetic induction. 2)Ultrasonic blood flow meter-Based on the principle if Doppler. 3)Thermal convection-The rate of cooling is proportional to the rate of flow of the medium. This principle is also used to measure the gas flow. 4)Determination by Radiographic method-By the injection of a contrast medium into a blood vessel, the circulation pattern can be made visible. Record of the X-ray image, obstruction can be detected and the blood flow in the blood vessels can be estimated. This technique is known as angiography”.

10)What is cardiac output?The blood flow at any point in the circulatory system is the volume of blood that passes that point during a unit of time .It is measured normally in millimeter per min or liters per min .Blood flow is highest in the pulmonary artery and the aorta, where the blood vessels leave the heart. The flow at these points is called ‘cardiac output’.

11)What is meant by pH? pH can be defined as the logarithm of the reciprocal of the H+ ion concentration. It is a measure of the acid-base balance of a fluid. pH= - log10 [H+] = log10( 1/[H+])

12)What is the pH value for blood? The pH value of normal arterial blood ranges between 7.38 and 7.42.The pH of venous blood is

MEDICAL ELECTRONICS

7.35,because of the extra CO2.13)Define GSR.

GSR is used for measuring variations in perspiration. In response to an external stimulus, such as touching a sharp point ,the resistance of the skin shows a characteristic decrease and this is known as Galvanic Skin Response. The GSR is believed to be caused by the activity of the sweat glands.

14)Give the name of the instrument used for respiratory volume measurements and what are its types? The most widely used instrument for respiratory volume measurements in the recording spirometer. The different types of spirometer are

· Standard spirometer · Waterless spirometer . Electronic spirometer · Wedge spirometer

Broncho spirometer

15) Give the name of the instrument used for measuring airflow and explain its principle.Pneumo tachometer can be used for measuring airflow. This device utilizes theprinciple that air flowing through an orifice produces a pressure difference across the orifice that is a function of the velocity of the air.16) Define MVV.

Maximal voluntary ventilation is a measure of the maximum amount of air that can be breathed in and blown out over a sustained interval, such as 15 or 20seconds.17)What is FVC?

Forced Vital Capacity (FVC) is the total amount of air that can forcibly be expired as quickly as possible after taking the deepest possible breath.

18)What is FRC? The functional residual capacity (FRC) is the volume of gas remaining in the lungs at the end expiratory level. It the sum of the residual volume and the expiratory reserve volume.

19)Differentiate between tidal volume and residual volume. The tidal volume (TV) or normal depth of breathing, is the volume of gasinspired or expired during each normal, quiet, respiration cycle.The residual volume (RV), is the volume of gas remaining in the lungs at theend of a maximal expiration.

20)Define total lung capacity.

Total Lung Capacity is the amount of gas contained in the lungs at the end of a maximal inspiration .It is also the sum of residual volume and vital capacity.

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PART - B

1)Explain the different methods of blood pressure measurements in detail.Indirect measurementsAutomated indirect methodsDirect measurements2) What are blood flow meters? Explain in detail about the ultrasonicblood flow meter?3)Explain in detail about the measurement of heart sounds.Measurement of heart sound4) Describe the measurement of gas volume in detail.Lung volume & capacities ,Mechanical measurementsInstrumentation for measuring the mechanics of breathing5)Define pH. Explain in detail the measurements of blood pH with neat sketches.

Unit-IV


1.Which are the elements of bio-telemetry system?

The essential elements are biological signal, transducer, conditioner, transmission link2.What are the types of radio telemetry systems?

Single channel telemetry systemRadio telemetry with a sub-carrierMultiple channel telemetry system

3.What are the types of multiple channel telemetry systems?

Frequency system multiplex Time division multiplex4. What are the measurements in single channel telemetry system?

Active measurements Passive measurements7.What are the types of transducer used in Ultrasonography?

Linear, Sector and Convex array8.What are the types of display modes used in Ultrasonography?

A-mode, B-mode and M-mode

9.What are the recording devices used in Ultrasonography?

MEDICAL ELECTRONICS

Strip chart recorder Video printer

Video recording Polaroid camera

10. .What are the artifacts in Ultrasonography?

Related to instrument problems

Improper operator technique

Due to interaction of sound.

11. Give the characteristics of X- Ray radiation .

When the fast moving electrons enters into the orbit of the anode material atom, its velocity is continuously decreased due to the scattering of the orbiting electrons. Thus the loss of energy of that incident electron appears in the form of continuous X-Rays or white X-Rays which are called Bremsstrahlung Radiation.

12. Define Efficiency.

Effiency is defined as the ratio of X-Ray beam energy to the electron beam energy which is normally 1.4*10-9ZVA. Where Z is the atomic number of anode material ,VA anode voltage normally in diagnosing radiology, tungsten is used as the anode material which has high melting point of about 33700C its atomic number Z=74The minimum wavelength emitted by the X-Ray is given by

lmin = hc/eva = 12408/VA Ao13. What is meant by soft and hard X-Ray ?

The anode voltage increases the l min decreases and henace X-Rays are called as hard X-Ray .These are mainly used for therapeautic purpose .If the anode voltage VA decreases then lmin increases and these are called soft X-Ray .14.List the basic components of X-Ray Machine

1.Power supply arrangement ,2.Collimator ,3.Diaphragm

4.Flim ,5.Lead shield

15.Define contrast.

It is a measure of darkness of a desired image compare to its surroundings. The contrast between two tissues is given by

C 12=10log I1/I2 dB

16.State the use of Bucky Diaphragm.

MEDICAL ELECTRONICS

It is introduced between the patient and the film to improve the sharpness of the image .It consists of thin lead veins separated by spaces of a low attenuation material. The lead veins are usually angled so that the primary radiation which carries the information can pass between them while these scattered radiation from the object are observed

17. Why aluminum filter is used in X-Ray tube.

The emitted rays of unwanted frequencies increase the patient those and the decrease the image contrast. Aluminum filters observes the lowest X-Ray frequency and hence the intensity of low X-Ray frequencies incident on the patient is ready in use.Hence the negative effects produce by low frequency X-Rays are reduced.18.Expalin the function of collimatorBetween the patient and the X-Ray tube the collimator is placed .I t is an aperture diaphragm which restricts the beam falling on the patient. the necessary shaping of the X-Ray beam is done by it

19.State the classification of ArtifactIt can be classified into 4 types1.Noise Artifact2.Motion Artifact3.Artifact due to high differential absorption in the adjacent tissue4.Technical errors and computer Artifacts.

20.Define NMR

In the presence of large magnetic field the spinning of nucleus in the atom and its axis of rotation will process about the magnetic field. Each spin state has different energy. At equilibrium, the lower state has more nuclei than the higher state. Using RF radiation with an energy exactly equal to the energy difference between two nuclear energy states. One state can achieve population inversion by raising the nuclei from the lower energy states to the higher energy state .The excited nuclear spins will slowly return to its equilibrium. Emitting the RF called Nuclear Magnetic Resonance

PART - B

1) With neat diagram explain X-Ray machine?

2) With neat diagram explain Computer Tomography? 3) With neat diagram explain Ultrasonography? 4) With neat diagram explain MRI? 5) With neat diagram explain Laser Instrumentation?

MEDICAL ELECTRONICS

Unit V


1. What is a pacemaker?

Pacemaker is an electrical pulse generator that starts or maintains the normal heart rhythm (i.e) application of electrical pulses to the heart is pacing action.2. Explain the classification of pacemaker?

Pacemaker is broadly classified into internal & external pacemaker.Total AV block requires internal pacemaker. It has a mini energy of 10µJ-100µJ (5V,10mA,2ms).At a level of 400µJ, it causes Ventricular Fibrillation. Cardiac Standstill is obtained by external pacemaker.

3. What are the types of pacemaker?

i. Ventricular synchronous(fixed rate pulse)

ii. Ventricular asynchronous(stand by pacemaker)

iii.Ventricular inhibited(demand pacemaker)

iv. Atrial synchronous pacemaker.

v. Atrial sequential ventricular inhibited pacemaker.

4. Explain the application of ventricular asynchronous or stand by pacemaker?

Ventricular asynchronous or stand by pacemaker is basically a simpleastable multivibrator that produces a stimulus at a fixed rate irrespective of the heart rhythm.5. What are the application of ventricular inhibited pacemaker?

i. The R wave inhibited pacemaker allows the heart to pace at its normal rhythm when it is able to. If the R wave is missing for a preset period of time, the pacer will supply a stimulus.ii. When the sensor ( shielded inside the pacemaker) is slightly stressed or bent by the patient’s body activity, the pacemaker can automatically increase or decrease its rate.Thus it can match with the greater physical effort.

6. What is the application of atrial synchronous pacemaker?

i. This type of pacing is used for young patients with a mostly stable block.

ii. It is used in stress testing & coronary artery diseases, in the evaluation of severity of mitral stenosis & in the evaluation of various conduction mechanisms.

MEDICAL ELECTRONICS

iii. It has been used to terminate atrial flutter & paroxymal atrial tachycardia.

iv. It can act as a temporary pacemaker for the atrial fibrillation.

7. What is an atrial sequential ventricular inhibited pacemaker and mention

its advantage?

Atrial sequential ventricular inhibited pacemaker has the capability ofstimulating both the atria & ventricles and adopt its method of stimulation to the patient’s need .If atrial function fails, this pacemaker will stimulate the atrium & then sense the subsequent ventricular beat.

8. What is a defibrillator?

A defibrillator is an electronic device that creates a sustainedmyocardial polarisation of a patient’s heart in order to stop ventricular fibrillation or atrial fibrillation.

9 Explain ventricular fibrillation and how can it be eliminated?

Ventricular fibrillation is a serious cardiac energy resulting fromasynchronous contraction of the heart muscle. This uncoordinated movement of ventricle walls of the heart may result from coronary occlusion, electric shock or abnormalities of

10. What are the different types of defibrillators?

i. Internal Defibrillator

ii. External Defibrillator

a. AC. Defibrillator

b. DC. Defibrillator

c. Synchronous DC. Defibrillator

d. Square Pulse Defibrillator

e. Double Square Pulse Defibrillator

f. Biphasic DC Defibrillator

11.What are the different types of oxygenator?

Bubble oxygenator

Film oxygenator

MEDICAL ELECTRONICS

Membrane oxygenator

Liquid-Liquid oxygenator

12.Define Heart-Lung Machine?

Heart Lung machine replaces the functions of heart and lungs thereby providing the rest of the body with a continuous supply of oxygenated blood while the heart is stopped.

13.What are the requirements of ideal oxygenator?

Lower priming volume

Minimum trauma to blood

Simple, safe and reliable operation

Ensured sterilization

No micro embolus formation and

Short preparation time

14.What is the principle of Liquid-Liquid oxygenator?

The oxygen dissolved fluorides organic fluid and blood are flowing in the opposite directions and oxygenation of the blood takes place.

15.What is the principle of membrane oxygenator?

Effective oxygenation is obtained when oxygen and blood are running in opposite directions through a thin porous membrane.

16.What is the principle of film oxygenator?

Here the film of blood is spread on a rotating disc or metal screen and an oxygen mixture flows over this thin layer of blood.

17.What is the principle of bubble oxygenator?

MEDICAL ELECTRONICS

By bubbling the oxygen through a large column of blood and the making the flow of blood through a slanting path, the carbon dioxide is removed from the blood

18.Define oxygenator.

In oxygenator mixture of oxygen and 2 to 5 percentage of carbon dioxide is usually employed to avoid respiratory alkalosis. Every oxygenator should oxygenate up to 5 liters per minute of blood.

19.What are the types of blood pumps?

1.Pulsatile pumps 2.Non pulsatile pumps

20.Define heat exchanger

Heat exchanger is used to regulate the blood temperature and compensate for the heat exchange in or out of the oxygenator

PART - B

Unit V1) What are pacemakers? Explain in detail the demand pacemaker with neat sketch.2)What are defibrillators? Explain in detail any two types of defibrillators with neat diagram.3)With neat diagram, explain in detail about the muscle stimulator.4) With neat diagram explain Heart – Lung machine?5) With neat diagram explain Endoscope?

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ECE - III Yr - VI Sem - QB Formatted