Sunday, September 27, 2009
Monday, September 21, 2009
Kings and Queens of ECE - A
No. Name Date of Birth
1 Aiswarya.K 17.1.1988
2 Alaguvel.R 27.12.1989
3 Ambika.S 9.9.1989
4 Ananda Raj.K 29.7.1989
5 Anandha Baskaran. B 5.7.1989
6 Anandha Jothi. I 26.1.1988
7 Anbu Veeramani. K
8 Anitha. A 5.4.1989
9 Anna Malai. R 6.8.1989
10 Archana. E
11 Arul Selvan.R 19.3.1989
12 Asha Priya.M
13 Ashok Kumar.K 30.6.1989
14 Ashok Kumar.R 18.12.1988
15 Ashok Kumar.S 27.1.1989
16 Balaji.M 12.12.1988
17 Bala Murugan.V 13.3.1989
18 Bala Subramaniam.K 12.5.1988
19 Bethleha Raja.G
20 Bharathi.R 20.6.1989
21 Bhavani.R
22 Bhuvana. R 13.4.1989
23 Chandra Moulieswaran. S
24 Dasa Rathan.E 13.1.1989
25 Deepan. R 06.11.1988
26 Devendran.R 15.12.1988
27 Dhaya Nandhan. R
28 Dhivya. T 04.07.1989
29 Divahar. N
30 Divia. S
31 Ganesh. S 25.05.1989
32 Ganesh Babu. T 03.
33 Gaya Thri. P
34 Gomathi. S 14.09.1989
35 Gopi. P 12.04.1989
36 Hari Haran. K 13.02.1989
37 Hari Krishnan. M 30.04.1987
38 Hasan Udeen. A
39 Jaffer Shadik. B 01.03.1989
40 Jaga Dhambal. K 30.04.1989
41 Jana Rthanan. G 20.08.1989
42 Jaya Sankar. R 24.12.1988
43 Jaga Dheesan. G
44 Kailash. B 15.12.1989
45 Kalai Yarasan. K 07.01.1989
46 Kanda Samy. R 02.03.1989
47 Kani Mozhi. S 31.07.1989
48 Kannan. S
49 Karthik. M 04.06.1989
50 Karthi Keyan. S 11.09.1989
51 Kavas Kar. S 18.11.1988
52 Kavitha. S 17.10.1988
53 Keerthana. M
54 Kevin. P 13.07.1988
55 Kivraj Anand. C
56 Koushik Prasad. P 10.10.1989
57 Kurinji Malar. J
58 Lakshmi. N 30.12.1989
59 Lakshmi Kanthan. G 19.7.1989
60 Lavanya. S 05.05.1989
61 Sida Thadan
62 Mankor.
63 Pacha Muthu. 26.11.1987
64 Sugumar. 23.7.1986
Source
Teachers For all Semesters
First year
Non sem ECE-A ECE-B
Technical English Mr.K.Velmurgan
Engineering Mathematics-I Mr.Sridar, Mr.Ganesh
Engineering Physics Mrs.R.Renuka
Physics & Chemistry lab Mrs.R.Renuka, Mr.B.Somasundaram
Engineering Chemistry Mr.B.Somasundaram, Mrs.Madhavi
Engineering Graphics
Engineering Practices Lab
Computer Programming Mrs.E.Kavitha Mrs.Anbarasi
Electron Devices
Circuit Analysis Mrs.Ramya
Second year
III sem
Mathematics-III Mr.Vijayakumar
Electrical Machines Mr.Sakthivel
Data structures Mrs.Venidevi Mrs.Venidevi
Data structure lab Mrs.Venidevi Mrs.Venidevi
Electronic Circuits-I Mrs.M.phemina Selvi Mrs.M.phemina Selvi
Digital Electronics Mr.E.Velmurgan Mr.E.Velmurgan
Environmental Science & Engg Ms.P.Aruna Priya Ms.A.Shanthi
Electrical Machines lab
Electronic Devices & circuits Lab Mr.G. Sadiq Basha
IV sem
Random Process
Electronic Circuits II Mr.E.Velmurgan Mr.E.Velmurgan
Signals and systems Mr.J.Joseph Ignatious Mr.J.Joseph Ignatious
Linear Integrated circuits Mrs. Jayachitra
Measurement&Instrumentation Ms.P.Aruna Priya Ms.A.Shanthi
Linear Integrated circuits lab Ms.P.Aruna Priya
Digital electronics lab Mrs.Subraja
Electro magnetic fields Mrs.Uma maheswari
Electronics circuitsII&stimulation lab Mr.E.Velmurgan
Third year
V Sem
Numerical methods Mr.Vijayakumar
Communication Theory Mrs.M.phemina Selvi Mrs.M.phemina Selvi
Digital Signal Processing Mr.J.Joseph Ignatious Mr.J.Joseph Ignatious
Digital signal processing lab Mr.J.Joseph Ignatious
Transmission lines &Waveguides Mr.G. Sadiq Basha Mr.G. Sadiq Basha
Communication skills&seminar
Control systems Ms.P.Aruna Priya Ms.A.Shanthi
Microprocessor & its applications Mr.E.Velmurgan Mr.E.Velmurgan
Microprocessor & its applications lab Mr.E.Velmurgan
VI sem
Principles of Management Mr.E.Velmurgan Mr.E.Velmurgan
Digital communication Mrs.S.Jaya Mrs.S.Jaya
Computer Architecture Mr.S.Karal Marx
Medical Electronics Mrs.P.Sujatha Mrs.P.Sujatha
Professional skills and seminar Mr.Balasubbaramani
Computer networks Ms.P.Aruna Priya
Networks lab Ms.P.Aruna Priya Mr.E.Velmurgan
Antenna and wave propagation Mr.G. Sadiq Basha Mr.G. Sadiq Basha
Electronics system design lab Mr.G. Sadiq Basha
Communication system lab Mrs.Siva gama sundari Mrs.S.Jaya
Final Year
VII sem
Digital image processing Ms.P.Aruna Priya Mrs.P.Sujatha
Optical communication Mrs.S.Jaya Mrs.S.Jaya
High speed networks Mrs.Siva gama sundari Mrs.Siva gama sundari
Television and video engg Mr.Balasubbaramani Mr.Balasubbaramani
VLSI Design Mr.E.Velmurgan Mr.E.Velmurgan
VLSI Lab Mr.E.Velmurgan Mr.G. Sadiq Basha
Microwave Engineering Mr.S.parthiban
Optical &Microwave lab Mr.S.parthiban Mr.J.Joseph Ignatious
VIII sem
Mobile communication
Project Work
Source From
http://vrscetmmcs.blogspot.com/
Sunday, August 9, 2009
MICROWAVE ENGINEERING Question bank
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
ENGINEERING
QUESTION BANK
SUBJECT CODE : EC1403
SEM / YEAR
: VII / IV
SUBJECT NAME : MICROWAVE ENGINEERING
UNIT - I
BASIC MICROWAVE COMPONENTS
PART- A ( 2 marks)
1. State Faraday's rotation law.
2. State the properties of S matrix.
3. What are the reasons that low frequency parameters cannot be Measured in microwaves?
4. State the two parameters that describe a directional coupler? Define them.
5. State TEE junction theorems.
6. What is S matrix and write the S matrix of N port network?
7. What is meant by hybrid coupler?
8. Compare z parameters and ABCD parameters with S-parameters.
9. What are hybrid rings?
10.List the parameters that determine the performance of a directional coupler.
11. Explain the action of a rat-race junction.
12.Why are waveguide bends and twists constructed so that the direction of propagated energy is
gradually changed?
PART - B
1. a A three port circulator has an insertion loss of 1db, isolation of 20 db, VSWR =1.2
when all ports are matched terminated. Find S matrix and output power at port 2and 3 for an
input power of 100mw at port
(6)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
b. Explain the principle of operation of magic Tee and derive the S matrix of Magic Tee.
(10)
2. From the first principles derive the S matrix parameters of Directional coupler.
(16)
3. a) Is it possible to match all the 3 ports of a lossless reciprocal microwave component?
Prove the same.
(10)
b) Explain with diagrams waveguide corner,bends,twists.
(6)
4. a) What is an isolator? Write down S parameters.
(4)
b)A signal of power 32mw is fed into one of the collinear ports of a lossless H plane tee.
Determine the powers in the remaining ports when other ports are terminated by means of
matched load.
(12)
5.With relevant equations , explain the properties of S-matrix with corresponding proof.
(16)
UNIT II
TRANSFERRED ELECTRON DEVICES & AVALANCHE TRANSIT TIME DEVICES
PART- A ( 2 marks)
1.Define GUNN effect.
2. What is the necessary condition for an IMPATT to produce oscillations?
3. List the differences between microwave transistor and TED devices.
4. What are the advantages and disadvantages of parametric amplifier?
5. What is meant by avalanche transit time device?
6. Discuss the applications of PIN diode.
7. What is a parametric amplifier? How is it different from a normal amplifier?
8. What is the theory of a negative resistance amplifier?
9. Explain how a tunnel diode can be used as a amplifier.
10.List the several donation formation modes of a Gunn diode.
11.State the performance characteristics of IMPATT and TRAPATT diode.
12. An IMPATT diode has a drift length of 2 um. Determine the operating frequency of IMPATT
diode if the drift velocity for Si is 107 cms/sec
PART- B
1. a) Derive the Manley Rowe power relation.
(12)
b) Use the above relation to find the power gain of an up and down converter.
(4)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
2. a) Using RWH theory , explain two valley model of GaAs.
(8)
b) Explain different types of modes.
(8)
3. Explain the working principle of IMPATT diode and derive the power output and efficiency? (16)
4. Explain the working principle of TRAPATT diode and derive the power output and efficiency?
(16)
5. Explain the working principle and modes of microwave bipolar transistor
(16)
6. Explain the working principle and operation of microwave FET.
(16)
UNIT III
MICROWAVE LINEAR BEAM TUBES & MICROWAVE CROSSED FIELD
TUBES
PART- A ( 2 marks)
1. Draw the electronic admittance diagram of reflex klystron.
2. State the differences between TWT and klystron?
3. Can a two cavity klystron amplifier be used an oscillator? If yes, how?
4. What is the purpose of slow wave structures in TWT?
5. What is meant by frequency pushing and frequency pulling?.
6. What is velocity modulation?
7. What are the limitations of conventional tubes at microwave frequencies?Explain how these
limitations can be overcome.
8. What are the performance characteristics of a Klystron amplifier?
9. How is bunching achieved in a cavity magnetron?
10. What are cross field deices?
11. How is tuning achieved in reflex klystron oscillators?
12. What is strapping in magnetron? How is the same effect obtained without strapping?
PART- B
1. With neat circuit diagrams and relevant equations, explain the velocity modulation
process and bunching in a klystron amplifier?.
(16)
2. Explain in detail about multicavity klystron amplifiers.
(16)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
3. Derive the equation for power output and efficiency of two cavities
and four cavity klystron amplifiers.
(16)
4. With neat diagrams and relevant equations, explain about helix
traveling wave tube.
(16)
5. With neat diagrams and relevant equations, explain about cylindrical and coaxial magnetron.
(16)
6. Discuss in detail about tunable magnetron and also explain in brief regarding Ricke diagram.
(16)
UNIT IV
STRIP LINES AND MONOLITHIC MICROWAVE INTEGRATED CIRCUITS
PART- A ( 2 marks)
1. What are the advantages of microstrip line over strip line?
2. What are the advantages of MMIC over discrete circuit?
3. What are the properties of dielectric materials?
4. What are the losses in strip lines?
5. List the various MMIC fabrication techniques.
6. Microstrip line is also called an open strip line.Comment on this.
7. Why is it difficult to establish microstrip short circuits?
8. What are the design considerations for a microstrip line?
9. Why are propagating modes along the strip lines are non-TEM and not pure TEM modes?
10.How are waveguides different from normal two - wire transmission lines?
11.Give the physical interpretation for phase and group velocity in relation to speed of light.
PART- B
1. Explain in detail about microstrip lines and derive the expression for characteristic
impedance of microstrip lines
(16)
2. Discuss in detail about the various losses in microstrip lines.
(16)
3. Explain the different types of microstrip lines and give a brief note of their characteristics. (16)
4. Write a brief note on the different types of materials and list their
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
characteristics,
(16)
5. Discuss in detail about the fabrication techniques of MMIC circuits.
(16)
UNIT V
MICROWAVE MEASUREMENTS
PART- A ( 2 marks)
1. What is Bolometer? Give two examples?
2. A wave guide load is used to absorb power of 2W., reflected power is 3mW.Find magnitude of
VSWR.
3. Why reflex klystron is a square wave 1kHz PAM while microwave measurements are done using
VSWR?
4. What are the sources of error in return loss measurement using a waveguide reflectometer and
klystron source?
5. What is meant by duty cycle?
6. How are microwave measurements different from low frequency measurements?
7. List the various techniques of measuring unknown frequency of a microwave generator.
8. How can you extend the range of power measurement?
9. Describe how an ordinary voltmeter can be calibrated to VSWR directly.What are the drawbacks
of such a VSWR meter?
10. List any two methods of measuring impedance of a terminating load in a microwave system.
11. Explain the concept of double minimum method of measuring VSWR.
PART- B
1. Explain in detail the measurement of VSWR through return loss measurements.
(16)
2. Discuss in detail the power measurement using microwave devices.
(16)
3. Write a brief note on insertion loss and attenuation measurements.
(16)
4. Explain in detail about the dielectric constant measurement of a solid using waveguide. (16)
5. Discuss in detail the impedance measurement using microwave devices.
(16)
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ENGINEERING
QUESTION BANK
SUBJECT CODE : EC1403
SEM / YEAR
: VII / IV
SUBJECT NAME : MICROWAVE ENGINEERING
UNIT - I
BASIC MICROWAVE COMPONENTS
PART- A ( 2 marks)
1. State Faraday's rotation law.
2. State the properties of S matrix.
3. What are the reasons that low frequency parameters cannot be Measured in microwaves?
4. State the two parameters that describe a directional coupler? Define them.
5. State TEE junction theorems.
6. What is S matrix and write the S matrix of N port network?
7. What is meant by hybrid coupler?
8. Compare z parameters and ABCD parameters with S-parameters.
9. What are hybrid rings?
10.List the parameters that determine the performance of a directional coupler.
11. Explain the action of a rat-race junction.
12.Why are waveguide bends and twists constructed so that the direction of propagated energy is
gradually changed?
PART - B
1. a A three port circulator has an insertion loss of 1db, isolation of 20 db, VSWR =1.2
when all ports are matched terminated. Find S matrix and output power at port 2and 3 for an
input power of 100mw at port
(6)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
b. Explain the principle of operation of magic Tee and derive the S matrix of Magic Tee.
(10)
2. From the first principles derive the S matrix parameters of Directional coupler.
(16)
3. a) Is it possible to match all the 3 ports of a lossless reciprocal microwave component?
Prove the same.
(10)
b) Explain with diagrams waveguide corner,bends,twists.
(6)
4. a) What is an isolator? Write down S parameters.
(4)
b)A signal of power 32mw is fed into one of the collinear ports of a lossless H plane tee.
Determine the powers in the remaining ports when other ports are terminated by means of
matched load.
(12)
5.With relevant equations , explain the properties of S-matrix with corresponding proof.
(16)
UNIT II
TRANSFERRED ELECTRON DEVICES & AVALANCHE TRANSIT TIME DEVICES
PART- A ( 2 marks)
1.Define GUNN effect.
2. What is the necessary condition for an IMPATT to produce oscillations?
3. List the differences between microwave transistor and TED devices.
4. What are the advantages and disadvantages of parametric amplifier?
5. What is meant by avalanche transit time device?
6. Discuss the applications of PIN diode.
7. What is a parametric amplifier? How is it different from a normal amplifier?
8. What is the theory of a negative resistance amplifier?
9. Explain how a tunnel diode can be used as a amplifier.
10.List the several donation formation modes of a Gunn diode.
11.State the performance characteristics of IMPATT and TRAPATT diode.
12. An IMPATT diode has a drift length of 2 um. Determine the operating frequency of IMPATT
diode if the drift velocity for Si is 107 cms/sec
PART- B
1. a) Derive the Manley Rowe power relation.
(12)
b) Use the above relation to find the power gain of an up and down converter.
(4)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
2. a) Using RWH theory , explain two valley model of GaAs.
(8)
b) Explain different types of modes.
(8)
3. Explain the working principle of IMPATT diode and derive the power output and efficiency? (16)
4. Explain the working principle of TRAPATT diode and derive the power output and efficiency?
(16)
5. Explain the working principle and modes of microwave bipolar transistor
(16)
6. Explain the working principle and operation of microwave FET.
(16)
UNIT III
MICROWAVE LINEAR BEAM TUBES & MICROWAVE CROSSED FIELD
TUBES
PART- A ( 2 marks)
1. Draw the electronic admittance diagram of reflex klystron.
2. State the differences between TWT and klystron?
3. Can a two cavity klystron amplifier be used an oscillator? If yes, how?
4. What is the purpose of slow wave structures in TWT?
5. What is meant by frequency pushing and frequency pulling?.
6. What is velocity modulation?
7. What are the limitations of conventional tubes at microwave frequencies?Explain how these
limitations can be overcome.
8. What are the performance characteristics of a Klystron amplifier?
9. How is bunching achieved in a cavity magnetron?
10. What are cross field deices?
11. How is tuning achieved in reflex klystron oscillators?
12. What is strapping in magnetron? How is the same effect obtained without strapping?
PART- B
1. With neat circuit diagrams and relevant equations, explain the velocity modulation
process and bunching in a klystron amplifier?.
(16)
2. Explain in detail about multicavity klystron amplifiers.
(16)
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
3. Derive the equation for power output and efficiency of two cavities
and four cavity klystron amplifiers.
(16)
4. With neat diagrams and relevant equations, explain about helix
traveling wave tube.
(16)
5. With neat diagrams and relevant equations, explain about cylindrical and coaxial magnetron.
(16)
6. Discuss in detail about tunable magnetron and also explain in brief regarding Ricke diagram.
(16)
UNIT IV
STRIP LINES AND MONOLITHIC MICROWAVE INTEGRATED CIRCUITS
PART- A ( 2 marks)
1. What are the advantages of microstrip line over strip line?
2. What are the advantages of MMIC over discrete circuit?
3. What are the properties of dielectric materials?
4. What are the losses in strip lines?
5. List the various MMIC fabrication techniques.
6. Microstrip line is also called an open strip line.Comment on this.
7. Why is it difficult to establish microstrip short circuits?
8. What are the design considerations for a microstrip line?
9. Why are propagating modes along the strip lines are non-TEM and not pure TEM modes?
10.How are waveguides different from normal two - wire transmission lines?
11.Give the physical interpretation for phase and group velocity in relation to speed of light.
PART- B
1. Explain in detail about microstrip lines and derive the expression for characteristic
impedance of microstrip lines
(16)
2. Discuss in detail about the various losses in microstrip lines.
(16)
3. Explain the different types of microstrip lines and give a brief note of their characteristics. (16)
4. Write a brief note on the different types of materials and list their
EC1403 - MICROWAVE ENGINEERING
Kings College Of Engineering, Punalkulam
characteristics,
(16)
5. Discuss in detail about the fabrication techniques of MMIC circuits.
(16)
UNIT V
MICROWAVE MEASUREMENTS
PART- A ( 2 marks)
1. What is Bolometer? Give two examples?
2. A wave guide load is used to absorb power of 2W., reflected power is 3mW.Find magnitude of
VSWR.
3. Why reflex klystron is a square wave 1kHz PAM while microwave measurements are done using
VSWR?
4. What are the sources of error in return loss measurement using a waveguide reflectometer and
klystron source?
5. What is meant by duty cycle?
6. How are microwave measurements different from low frequency measurements?
7. List the various techniques of measuring unknown frequency of a microwave generator.
8. How can you extend the range of power measurement?
9. Describe how an ordinary voltmeter can be calibrated to VSWR directly.What are the drawbacks
of such a VSWR meter?
10. List any two methods of measuring impedance of a terminating load in a microwave system.
11. Explain the concept of double minimum method of measuring VSWR.
PART- B
1. Explain in detail the measurement of VSWR through return loss measurements.
(16)
2. Discuss in detail the power measurement using microwave devices.
(16)
3. Write a brief note on insertion loss and attenuation measurements.
(16)
4. Explain in detail about the dielectric constant measurement of a solid using waveguide. (16)
5. Discuss in detail the impedance measurement using microwave devices.
(16)
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OPTICAL COMMUNICATION Question bank
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
ENGINEERING
QUESTION BANK
SUBJECT CODE
: EC1402
SEM / YEAR :
VII/ IV
SUBJECT NAME : OPTICAL COMMUNICATION
UNIT - I
INTRODUCTION TO OPTICAL FIBERS
PART- A ( 2 marks)
1. Among Microwaves and light waves which have high bit rate distance product?Why?
2. Mention the three advantages of optical fiber as waveguide over conventional
metallic waveguide?
3. What is meant by mode and index profile?
4. Mention the advantages of Graded Index fiber.
5. Write the expression for the refractive index in Graded index fiber.
6. Define Numerical Aperture of step index fiber.
7. Give the expression of the effective number of modes that are guided by a curved
multimode fiber of radius ' a'.
8. State Snells Law.
9. Define Critical angle?
10.Define TIR?
11.What is the need of Cladding?
12.Define core index difference.
13.Define refractive index?
14.What are leaky modes in optical fibers?
15.Define External reflection of light rays?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
16.What is meant by modes of waveguide?
17.Define V number?
18.What is relation between V number and power flow in cladding?
19.What is the fundamental parameter of SM fiber?
20.Give the relation between rays and modes?
21.What are the advantages and disadvantages of SM fiber?
22.What are the advantages and disadvantages of MM fiber?
23.Define skew rays and merdional rays?
24.Define cutoff conditions?
25.What is meant by Degenerate modes?
26.What is meant by linearly polarized modes?
27.Define MFD?
28.Define Bi refrigence and beat length?
29.A point source of light is 12cm below the surface of a large body of water (n=1.33).
What is the radius of the largest circle on the water surface through which the lights
can emerge?
30.Consider a parabolic index waveguide with n
1
=1.75,n
2
=1.677 and core radius 52um.
Calculate the numerical aperture at the axis and at a point 20um from the axis.
31.Why do we prefer step index single mode fiber for long distance communication?
32.Why do we use LP
01
mode for long distance communications?
33.What are three operating windows?
34.Alight ray is incident from glass to air. Calculate critical angle?
PART - B
1. What are Fiber modes? Explain mode theory for optical fiber in detail?
(16)
2. Compare SM fiber and Graded index fiber. Explain the requirements for fiber
materials?
(16)
3. Discuss the theory of GI fiber. Derive the expression for the numerical aperture of GI
fiber?
(16)
4. Derive an expression for number of modes propagating in GI fiber from the first
principle .
(16)
5. i) Mention the advantages of optical communication systems?
(8)
ii) Draw the elements of an optical communication systems?
(8)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
6. i) Discuss the propagation modes in SM fiber
(8)
ii)Briefly explain the evolution of fiber optic systems?
(8)
6. i)Compare the configurations of different types of fibers?
(8)
ii) Discuss the modes in Step index fiber?
(8)
7. i)Derive the wave equations for step index fiber and explain?
(8)
ii)Sketch and explain the electric field distributions of low order guided modes in
symmetrical slab waveguide?
(8)
8. A fiber has normalized frequency is 26.6 and wavelength is 1300nm.If the
radius of core is 25um.Compute numerical aperture?
(16)
9. a) A multimode step index fiber with core diameter of 80um and index difference of
1.5% at wavelength of 0.85um.If the refractive is 1.48,find normalized frequency and
no of modes?
(8)
b) Derive the expression for power flow in step index fiber?
(8)
10.a)Explain Linearly polarized modes?
(8)
b)The relative index difference in graded index fiber is 0.7% ,core refractive is
1.45.Find numerical aperture when index profile is triangular.
(8)
11 a).Derive modal equation.
(8)
b) Compare single and multimode fiber.
(8)
UNIT II
SIGNAL DEGRADATION OPTICAL FBERS
PART- A ( 2 marks)
1. An optical signal has lost 55% of its power after traversing 3.5 km of fiber. What is
the loss in dB/km of this fiber?
2. Define mode-field diameter.
3. What are the causes of absorption?
4. Define normalized propagation constant.
5. List the basic attenuation mechanisms in an optical fiber.
6. What is meant be mode coupling ? What causes it ?
7. Mention the two causes of intramodal dispersion.
8. Define fiber loss.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
9. What do you mean be polarization mode dispersion?
10.Commonly available single mode fibers have beat lengths in the range 10cm
11.Find the coupling loss for two fibers having core refractive index profiles α
E
=2.0
and α
R
=1.5
12.Define Raleigh Scattering loss.
13.Define Mie Scattering loss.
14.When the mean optical power launched into an 8 km length of fiber is 120 uw.
Determine the overall signal attenuation or loss in decibels.
15.How are micro bending losses reduced?
16.Distinguish intrinsic and extrinsic absorption.
17.Distinguish dispersion shifted and dispersion flattened fibers.
PART-B
1. What is meant by waveguide dispersion ? Derive the expression for the same. (16)
2. What is meant be material dispersion ? Derive the expression for the pulse
broadening due to material dispersion.
(16)
3. Discuss the signal distortion in single mode fibers.
(16)
4. Sketch the fundamental mode field in a curved optical wave guide and explain how
bending losses occur.
(16)
5. Explain with suitable diagrams the different mechanisms that contribute to attenuation
in optical fibers.
(16)
6. When the mean optical power launched into an 8km length of fiber is 120 uW, the
mean optical power at the fiber output is 3u W.
Determine
(1) Overall signal attenuation in dB/km and
(8)
(2) The overall signal attenuation for a 10km intervals, each giving an attenuation of
1dB.
(8)
7. Explain in detail mode coupling and design optimization of single mode fibers. (16)
8. Discuss in detail intermodal dispersion of multimode step index fiber with relevant
expression and diagrams.
(16)
9. What is mode coupling ? Discuss pulse broadening in GI fibers.
(16)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
10.Discuss various kinds of losses that an optical signal might suffer while propagating
through fiber. Which is most important one? What is the effect of these losses on
light power and pulse shape?
(16)
11.A 6 km optical link consists of multimode step index with a core refractive index of 1.5
and a relative refractive index difference of 1%. Estimate the delay difference
between the slowest and fastest modes at the fiber output and the rms broadening
due to intermodal dispersion on the link. Also derive the expression involved in it.
(16)
UNIT III
FIBER OPTCAL SOURCES AND COUPLING
PART- A ( 2 marks)
1.
Define radiance.
2.
What is meant by " population inversion"?
3.
what is meant by heterojunction?
4.
What is meant by indirect band gap semiconductor material?
5.
Draw the three key transition processes involved in laser action.
6.
Give examples for direct and indirect semiconductor materials.
7.
Define internal quantum efficiency of an LED.
8.
Name few splicing methods in fiber optics.
9.
Compare LED and LASER.
10.
What so you mean by heterojunction ? Mention its advantages.
a. List the different types of mechanical misalignments that can occur between
two joined fibers.
b. Calculate the ratio of stimulated emission rata to the spontaneous emission
rate for a lamp operating at a temperature of 1000 K. Assume average
operating wavelength is 0.5um.
11.
Define lambertian pattern .
12.
Define FWHM.
13.
Define Modal or speckle noise.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
14.
Define " Kinks".
15.
Define Mode partition noise.
16.
Define Lensing Schemes.
17.
Define Splicing ? What are types of Splicing.?
18.
What are the Characteristics of Light Source .
PART - B
1. Draw the two basic LED configurations and discuss the principle.
(16)
2. Discuss the principle of optical feedback and LASER oscillation.
(16)
3. Derive the threshold condition for LASER oscillation.
(16)
4. Explain various fiber splicing techniques.
(16)
5. Write technical notes on optical fiber connectors.
(16)
6. Discuss the laser diode structures and radiation patterns.(16)
7. Draw the structures of edge - emitting LED and surface emitting LED and
explain the operation.
(16)
8. Discuss the LASER diode principle , modes and threshold conditions.
(16)
9. Explain various types of fiber splicing techniques and fiber connectors.
(16)
10. Derive the threshold condition for LASER
(16)
11. Explain the laser action with neat diagrams.
(16)
12.a) A GaAs laser operating at 850 nm has a 500 um length and a refractive index
n = 3.7. What are the frequency and wavelength spacings?
(6)
b) With neat diagram explain the construction and working of high radiance surface
Emitting LED.
(10)
13. Discuss about modulation of laser diodes. Why thermoelectric coolers are used in
laser diodes.
(16)
14.Discuss in detail fiber splicing and connectors. Explain the operation principles of
WDM.
(16)
15.Draw and explain the LED structures based double hetero structure configuration.(16)
16.Discuss the principles of operation of laser diodes. What are the effects of temperature
on the performance of a laser diode?
(16)
17.Explain in different lensing schemes available to improve the power coupling
efficiency.
(16)
EC1402 OPTICAL COMMUNICATIONS
18.Explain the fiber splicing techniques with necessary diagrams.
(16)
UNIT - IV
FIBER OPTICAL RECEIVERS
PART- A ( 2 marks)
1. Define diffusion length.
2. Define avalanche effect .
3. Define responsivity.
4. Define Quantum efficiency of photo detector.
5. Write the noise sources in the receiver section.
6.Define Quantum limit.
7.What are the desired features of photo detector.
8.A photo diode is constructed of GaAs which has a bandgap energy of 1.43Ev at 300k.
What is meant by long wavelength cutoff?
9.What are the benefits of trans impedance amplifier.
10.Define long wave length cutoff related photo diode.
11.What is meant by bulk dark current?
12.A photo diode has a capacitance of 6pf.Calculate the max load resistance which allows
an 8MHz post defection BW.
13. What is meant by impact ionization. In APD?
14.What is transit time of photo carriers?
15.What is meant by ionization rate?
16. Define avalanche multiplication?
17.Define S/N ratio of an optical receiver?What are the conditions are required
to achieve high S/N?
18.Define BER?
19.Define Extinction ratio?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
20. Define photo current?
21. What is p+ πpn+ reach through structure?
22.Define excess noise factor?
23. What is meant by Pre amplifier? What are the advantages of pre amplifier?
24.Whar are the draw backs of high impedance amplifier?
PART - B
1. Describe the working principle of PIN photo detector and explain the characteristics
of pin diode.
(16)
2. Explain with neat diagram, construction and working of APD. Compare photo
detectors.
(16)
3. Discuss the different noise sources and disturbances in the optical pulse detection
mechanism and derive the expression of S/N ratio.
(16)
4. a) Explain the fundamental receiver operation in optical communication.
(6)
b)Derive an expression for the bit error rate of an optical receiver.
(10)
5. Discuss the source of errors in optical receivers
(16)
6. The Quantum efficency of a RAPD is 80% for thr detection of radiation at 0.9um,
when incident optical power is 0.5uw.The output current from the device(after
avalance gain) is 11 uA. Determine avalanche multiplication factor?
(16)
UNIT - V
DIGITAL TRANSMISSION SYSTEM
PART- A ( 2 marks)
1. List out the requirements that are to be considered in analyzing a link
2. Differentiate link power budget and rise time budget.
3. What is SONET? How does it differ from SDH?
4. What are solitons?
5. What is meant by 'modal noise'?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
PART-B
1. Write notes on LINK POWER BUDGET.
(16)
2. Write notes on RISE TIME BUDGET.
(16)
3. Write notes on SONET.
(16)
4. List out the WDM components. Explain them briefly.
(16)
5. Discuss the principles, requirements and applications of WDM.
(16)
--
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ENGINEERING
QUESTION BANK
SUBJECT CODE
: EC1402
SEM / YEAR :
VII/ IV
SUBJECT NAME : OPTICAL COMMUNICATION
UNIT - I
INTRODUCTION TO OPTICAL FIBERS
PART- A ( 2 marks)
1. Among Microwaves and light waves which have high bit rate distance product?Why?
2. Mention the three advantages of optical fiber as waveguide over conventional
metallic waveguide?
3. What is meant by mode and index profile?
4. Mention the advantages of Graded Index fiber.
5. Write the expression for the refractive index in Graded index fiber.
6. Define Numerical Aperture of step index fiber.
7. Give the expression of the effective number of modes that are guided by a curved
multimode fiber of radius ' a'.
8. State Snells Law.
9. Define Critical angle?
10.Define TIR?
11.What is the need of Cladding?
12.Define core index difference.
13.Define refractive index?
14.What are leaky modes in optical fibers?
15.Define External reflection of light rays?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
16.What is meant by modes of waveguide?
17.Define V number?
18.What is relation between V number and power flow in cladding?
19.What is the fundamental parameter of SM fiber?
20.Give the relation between rays and modes?
21.What are the advantages and disadvantages of SM fiber?
22.What are the advantages and disadvantages of MM fiber?
23.Define skew rays and merdional rays?
24.Define cutoff conditions?
25.What is meant by Degenerate modes?
26.What is meant by linearly polarized modes?
27.Define MFD?
28.Define Bi refrigence and beat length?
29.A point source of light is 12cm below the surface of a large body of water (n=1.33).
What is the radius of the largest circle on the water surface through which the lights
can emerge?
30.Consider a parabolic index waveguide with n
1
=1.75,n
2
=1.677 and core radius 52um.
Calculate the numerical aperture at the axis and at a point 20um from the axis.
31.Why do we prefer step index single mode fiber for long distance communication?
32.Why do we use LP
01
mode for long distance communications?
33.What are three operating windows?
34.Alight ray is incident from glass to air. Calculate critical angle?
PART - B
1. What are Fiber modes? Explain mode theory for optical fiber in detail?
(16)
2. Compare SM fiber and Graded index fiber. Explain the requirements for fiber
materials?
(16)
3. Discuss the theory of GI fiber. Derive the expression for the numerical aperture of GI
fiber?
(16)
4. Derive an expression for number of modes propagating in GI fiber from the first
principle .
(16)
5. i) Mention the advantages of optical communication systems?
(8)
ii) Draw the elements of an optical communication systems?
(8)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
6. i) Discuss the propagation modes in SM fiber
(8)
ii)Briefly explain the evolution of fiber optic systems?
(8)
6. i)Compare the configurations of different types of fibers?
(8)
ii) Discuss the modes in Step index fiber?
(8)
7. i)Derive the wave equations for step index fiber and explain?
(8)
ii)Sketch and explain the electric field distributions of low order guided modes in
symmetrical slab waveguide?
(8)
8. A fiber has normalized frequency is 26.6 and wavelength is 1300nm.If the
radius of core is 25um.Compute numerical aperture?
(16)
9. a) A multimode step index fiber with core diameter of 80um and index difference of
1.5% at wavelength of 0.85um.If the refractive is 1.48,find normalized frequency and
no of modes?
(8)
b) Derive the expression for power flow in step index fiber?
(8)
10.a)Explain Linearly polarized modes?
(8)
b)The relative index difference in graded index fiber is 0.7% ,core refractive is
1.45.Find numerical aperture when index profile is triangular.
(8)
11 a).Derive modal equation.
(8)
b) Compare single and multimode fiber.
(8)
UNIT II
SIGNAL DEGRADATION OPTICAL FBERS
PART- A ( 2 marks)
1. An optical signal has lost 55% of its power after traversing 3.5 km of fiber. What is
the loss in dB/km of this fiber?
2. Define mode-field diameter.
3. What are the causes of absorption?
4. Define normalized propagation constant.
5. List the basic attenuation mechanisms in an optical fiber.
6. What is meant be mode coupling ? What causes it ?
7. Mention the two causes of intramodal dispersion.
8. Define fiber loss.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
9. What do you mean be polarization mode dispersion?
10.Commonly available single mode fibers have beat lengths in the range 10cm
11.Find the coupling loss for two fibers having core refractive index profiles α
E
=2.0
and α
R
=1.5
12.Define Raleigh Scattering loss.
13.Define Mie Scattering loss.
14.When the mean optical power launched into an 8 km length of fiber is 120 uw.
Determine the overall signal attenuation or loss in decibels.
15.How are micro bending losses reduced?
16.Distinguish intrinsic and extrinsic absorption.
17.Distinguish dispersion shifted and dispersion flattened fibers.
PART-B
1. What is meant by waveguide dispersion ? Derive the expression for the same. (16)
2. What is meant be material dispersion ? Derive the expression for the pulse
broadening due to material dispersion.
(16)
3. Discuss the signal distortion in single mode fibers.
(16)
4. Sketch the fundamental mode field in a curved optical wave guide and explain how
bending losses occur.
(16)
5. Explain with suitable diagrams the different mechanisms that contribute to attenuation
in optical fibers.
(16)
6. When the mean optical power launched into an 8km length of fiber is 120 uW, the
mean optical power at the fiber output is 3u W.
Determine
(1) Overall signal attenuation in dB/km and
(8)
(2) The overall signal attenuation for a 10km intervals, each giving an attenuation of
1dB.
(8)
7. Explain in detail mode coupling and design optimization of single mode fibers. (16)
8. Discuss in detail intermodal dispersion of multimode step index fiber with relevant
expression and diagrams.
(16)
9. What is mode coupling ? Discuss pulse broadening in GI fibers.
(16)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
10.Discuss various kinds of losses that an optical signal might suffer while propagating
through fiber. Which is most important one? What is the effect of these losses on
light power and pulse shape?
(16)
11.A 6 km optical link consists of multimode step index with a core refractive index of 1.5
and a relative refractive index difference of 1%. Estimate the delay difference
between the slowest and fastest modes at the fiber output and the rms broadening
due to intermodal dispersion on the link. Also derive the expression involved in it.
(16)
UNIT III
FIBER OPTCAL SOURCES AND COUPLING
PART- A ( 2 marks)
1.
Define radiance.
2.
What is meant by " population inversion"?
3.
what is meant by heterojunction?
4.
What is meant by indirect band gap semiconductor material?
5.
Draw the three key transition processes involved in laser action.
6.
Give examples for direct and indirect semiconductor materials.
7.
Define internal quantum efficiency of an LED.
8.
Name few splicing methods in fiber optics.
9.
Compare LED and LASER.
10.
What so you mean by heterojunction ? Mention its advantages.
a. List the different types of mechanical misalignments that can occur between
two joined fibers.
b. Calculate the ratio of stimulated emission rata to the spontaneous emission
rate for a lamp operating at a temperature of 1000 K. Assume average
operating wavelength is 0.5um.
11.
Define lambertian pattern .
12.
Define FWHM.
13.
Define Modal or speckle noise.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
14.
Define " Kinks".
15.
Define Mode partition noise.
16.
Define Lensing Schemes.
17.
Define Splicing ? What are types of Splicing.?
18.
What are the Characteristics of Light Source .
PART - B
1. Draw the two basic LED configurations and discuss the principle.
(16)
2. Discuss the principle of optical feedback and LASER oscillation.
(16)
3. Derive the threshold condition for LASER oscillation.
(16)
4. Explain various fiber splicing techniques.
(16)
5. Write technical notes on optical fiber connectors.
(16)
6. Discuss the laser diode structures and radiation patterns.(16)
7. Draw the structures of edge - emitting LED and surface emitting LED and
explain the operation.
(16)
8. Discuss the LASER diode principle , modes and threshold conditions.
(16)
9. Explain various types of fiber splicing techniques and fiber connectors.
(16)
10. Derive the threshold condition for LASER
(16)
11. Explain the laser action with neat diagrams.
(16)
12.a) A GaAs laser operating at 850 nm has a 500 um length and a refractive index
n = 3.7. What are the frequency and wavelength spacings?
(6)
b) With neat diagram explain the construction and working of high radiance surface
Emitting LED.
(10)
13. Discuss about modulation of laser diodes. Why thermoelectric coolers are used in
laser diodes.
(16)
14.Discuss in detail fiber splicing and connectors. Explain the operation principles of
WDM.
(16)
15.Draw and explain the LED structures based double hetero structure configuration.(16)
16.Discuss the principles of operation of laser diodes. What are the effects of temperature
on the performance of a laser diode?
(16)
17.Explain in different lensing schemes available to improve the power coupling
efficiency.
(16)
EC1402 OPTICAL COMMUNICATIONS
18.Explain the fiber splicing techniques with necessary diagrams.
(16)
UNIT - IV
FIBER OPTICAL RECEIVERS
PART- A ( 2 marks)
1. Define diffusion length.
2. Define avalanche effect .
3. Define responsivity.
4. Define Quantum efficiency of photo detector.
5. Write the noise sources in the receiver section.
6.Define Quantum limit.
7.What are the desired features of photo detector.
8.A photo diode is constructed of GaAs which has a bandgap energy of 1.43Ev at 300k.
What is meant by long wavelength cutoff?
9.What are the benefits of trans impedance amplifier.
10.Define long wave length cutoff related photo diode.
11.What is meant by bulk dark current?
12.A photo diode has a capacitance of 6pf.Calculate the max load resistance which allows
an 8MHz post defection BW.
13. What is meant by impact ionization. In APD?
14.What is transit time of photo carriers?
15.What is meant by ionization rate?
16. Define avalanche multiplication?
17.Define S/N ratio of an optical receiver?What are the conditions are required
to achieve high S/N?
18.Define BER?
19.Define Extinction ratio?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
20. Define photo current?
21. What is p+ πpn+ reach through structure?
22.Define excess noise factor?
23. What is meant by Pre amplifier? What are the advantages of pre amplifier?
24.Whar are the draw backs of high impedance amplifier?
PART - B
1. Describe the working principle of PIN photo detector and explain the characteristics
of pin diode.
(16)
2. Explain with neat diagram, construction and working of APD. Compare photo
detectors.
(16)
3. Discuss the different noise sources and disturbances in the optical pulse detection
mechanism and derive the expression of S/N ratio.
(16)
4. a) Explain the fundamental receiver operation in optical communication.
(6)
b)Derive an expression for the bit error rate of an optical receiver.
(10)
5. Discuss the source of errors in optical receivers
(16)
6. The Quantum efficency of a RAPD is 80% for thr detection of radiation at 0.9um,
when incident optical power is 0.5uw.The output current from the device(after
avalance gain) is 11 uA. Determine avalanche multiplication factor?
(16)
UNIT - V
DIGITAL TRANSMISSION SYSTEM
PART- A ( 2 marks)
1. List out the requirements that are to be considered in analyzing a link
2. Differentiate link power budget and rise time budget.
3. What is SONET? How does it differ from SDH?
4. What are solitons?
5. What is meant by 'modal noise'?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
PART-B
1. Write notes on LINK POWER BUDGET.
(16)
2. Write notes on RISE TIME BUDGET.
(16)
3. Write notes on SONET.
(16)
4. List out the WDM components. Explain them briefly.
(16)
5. Discuss the principles, requirements and applications of WDM.
(16)
--
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OPTICAL COMMUNICATION Question bank
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
ENGINEERING
QUESTION BANK
SUBJECT CODE
: EC1402
SEM / YEAR :
VII/ IV
SUBJECT NAME : OPTICAL COMMUNICATION
UNIT - I
INTRODUCTION TO OPTICAL FIBERS
PART- A ( 2 marks)
1. Among Microwaves and light waves which have high bit rate distance product?Why?
2. Mention the three advantages of optical fiber as waveguide over conventional
metallic waveguide?
3. What is meant by mode and index profile?
4. Mention the advantages of Graded Index fiber.
5. Write the expression for the refractive index in Graded index fiber.
6. Define Numerical Aperture of step index fiber.
7. Give the expression of the effective number of modes that are guided by a curved
multimode fiber of radius ' a'.
8. State Snells Law.
9. Define Critical angle?
10.Define TIR?
11.What is the need of Cladding?
12.Define core index difference.
13.Define refractive index?
14.What are leaky modes in optical fibers?
15.Define External reflection of light rays?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
16.What is meant by modes of waveguide?
17.Define V number?
18.What is relation between V number and power flow in cladding?
19.What is the fundamental parameter of SM fiber?
20.Give the relation between rays and modes?
21.What are the advantages and disadvantages of SM fiber?
22.What are the advantages and disadvantages of MM fiber?
23.Define skew rays and merdional rays?
24.Define cutoff conditions?
25.What is meant by Degenerate modes?
26.What is meant by linearly polarized modes?
27.Define MFD?
28.Define Bi refrigence and beat length?
29.A point source of light is 12cm below the surface of a large body of water (n=1.33).
What is the radius of the largest circle on the water surface through which the lights
can emerge?
30.Consider a parabolic index waveguide with n
1
=1.75,n
2
=1.677 and core radius 52um.
Calculate the numerical aperture at the axis and at a point 20um from the axis.
31.Why do we prefer step index single mode fiber for long distance communication?
32.Why do we use LP
01
mode for long distance communications?
33.What are three operating windows?
34.Alight ray is incident from glass to air. Calculate critical angle?
PART - B
1. What are Fiber modes? Explain mode theory for optical fiber in detail?
(16)
2. Compare SM fiber and Graded index fiber. Explain the requirements for fiber
materials?
(16)
3. Discuss the theory of GI fiber. Derive the expression for the numerical aperture of GI
fiber?
(16)
4. Derive an expression for number of modes propagating in GI fiber from the first
principle .
(16)
5. i) Mention the advantages of optical communication systems?
(8)
ii) Draw the elements of an optical communication systems?
(8)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
6. i) Discuss the propagation modes in SM fiber
(8)
ii)Briefly explain the evolution of fiber optic systems?
(8)
6. i)Compare the configurations of different types of fibers?
(8)
ii) Discuss the modes in Step index fiber?
(8)
7. i)Derive the wave equations for step index fiber and explain?
(8)
ii)Sketch and explain the electric field distributions of low order guided modes in
symmetrical slab waveguide?
(8)
8. A fiber has normalized frequency is 26.6 and wavelength is 1300nm.If the
radius of core is 25um.Compute numerical aperture?
(16)
9. a) A multimode step index fiber with core diameter of 80um and index difference of
1.5% at wavelength of 0.85um.If the refractive is 1.48,find normalized frequency and
no of modes?
(8)
b) Derive the expression for power flow in step index fiber?
(8)
10.a)Explain Linearly polarized modes?
(8)
b)The relative index difference in graded index fiber is 0.7% ,core refractive is
1.45.Find numerical aperture when index profile is triangular.
(8)
11 a).Derive modal equation.
(8)
b) Compare single and multimode fiber.
(8)
UNIT II
SIGNAL DEGRADATION OPTICAL FBERS
PART- A ( 2 marks)
1. An optical signal has lost 55% of its power after traversing 3.5 km of fiber. What is
the loss in dB/km of this fiber?
2. Define mode-field diameter.
3. What are the causes of absorption?
4. Define normalized propagation constant.
5. List the basic attenuation mechanisms in an optical fiber.
6. What is meant be mode coupling ? What causes it ?
7. Mention the two causes of intramodal dispersion.
8. Define fiber loss.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
9. What do you mean be polarization mode dispersion?
10.Commonly available single mode fibers have beat lengths in the range 10cm
11.Find the coupling loss for two fibers having core refractive index profiles α
E
=2.0
and α
R
=1.5
12.Define Raleigh Scattering loss.
13.Define Mie Scattering loss.
14.When the mean optical power launched into an 8 km length of fiber is 120 uw.
Determine the overall signal attenuation or loss in decibels.
15.How are micro bending losses reduced?
16.Distinguish intrinsic and extrinsic absorption.
17.Distinguish dispersion shifted and dispersion flattened fibers.
PART-B
1. What is meant by waveguide dispersion ? Derive the expression for the same. (16)
2. What is meant be material dispersion ? Derive the expression for the pulse
broadening due to material dispersion.
(16)
3. Discuss the signal distortion in single mode fibers.
(16)
4. Sketch the fundamental mode field in a curved optical wave guide and explain how
bending losses occur.
(16)
5. Explain with suitable diagrams the different mechanisms that contribute to attenuation
in optical fibers.
(16)
6. When the mean optical power launched into an 8km length of fiber is 120 uW, the
mean optical power at the fiber output is 3u W.
Determine
(1) Overall signal attenuation in dB/km and
(8)
(2) The overall signal attenuation for a 10km intervals, each giving an attenuation of
1dB.
(8)
7. Explain in detail mode coupling and design optimization of single mode fibers. (16)
8. Discuss in detail intermodal dispersion of multimode step index fiber with relevant
expression and diagrams.
(16)
9. What is mode coupling ? Discuss pulse broadening in GI fibers.
(16)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
10.Discuss various kinds of losses that an optical signal might suffer while propagating
through fiber. Which is most important one? What is the effect of these losses on
light power and pulse shape?
(16)
11.A 6 km optical link consists of multimode step index with a core refractive index of 1.5
and a relative refractive index difference of 1%. Estimate the delay difference
between the slowest and fastest modes at the fiber output and the rms broadening
due to intermodal dispersion on the link. Also derive the expression involved in it.
(16)
UNIT III
FIBER OPTCAL SOURCES AND COUPLING
PART- A ( 2 marks)
1.
Define radiance.
2.
What is meant by " population inversion"?
3.
what is meant by heterojunction?
4.
What is meant by indirect band gap semiconductor material?
5.
Draw the three key transition processes involved in laser action.
6.
Give examples for direct and indirect semiconductor materials.
7.
Define internal quantum efficiency of an LED.
8.
Name few splicing methods in fiber optics.
9.
Compare LED and LASER.
10.
What so you mean by heterojunction ? Mention its advantages.
a. List the different types of mechanical misalignments that can occur between
two joined fibers.
b. Calculate the ratio of stimulated emission rata to the spontaneous emission
rate for a lamp operating at a temperature of 1000 K. Assume average
operating wavelength is 0.5um.
11.
Define lambertian pattern .
12.
Define FWHM.
13.
Define Modal or speckle noise.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
14.
Define " Kinks".
15.
Define Mode partition noise.
16.
Define Lensing Schemes.
17.
Define Splicing ? What are types of Splicing.?
18.
What are the Characteristics of Light Source .
PART - B
1. Draw the two basic LED configurations and discuss the principle.
(16)
2. Discuss the principle of optical feedback and LASER oscillation.
(16)
3. Derive the threshold condition for LASER oscillation.
(16)
4. Explain various fiber splicing techniques.
(16)
5. Write technical notes on optical fiber connectors.
(16)
6. Discuss the laser diode structures and radiation patterns.(16)
7. Draw the structures of edge - emitting LED and surface emitting LED and
explain the operation.
(16)
8. Discuss the LASER diode principle , modes and threshold conditions.
(16)
9. Explain various types of fiber splicing techniques and fiber connectors.
(16)
10. Derive the threshold condition for LASER
(16)
11. Explain the laser action with neat diagrams.
(16)
12.a) A GaAs laser operating at 850 nm has a 500 um length and a refractive index
n = 3.7. What are the frequency and wavelength spacings?
(6)
b) With neat diagram explain the construction and working of high radiance surface
Emitting LED.
(10)
13. Discuss about modulation of laser diodes. Why thermoelectric coolers are used in
laser diodes.
(16)
14.Discuss in detail fiber splicing and connectors. Explain the operation principles of
WDM.
(16)
15.Draw and explain the LED structures based double hetero structure configuration.(16)
16.Discuss the principles of operation of laser diodes. What are the effects of temperature
on the performance of a laser diode?
(16)
17.Explain in different lensing schemes available to improve the power coupling
efficiency.
(16)
EC1402 OPTICAL COMMUNICATIONS
18.Explain the fiber splicing techniques with necessary diagrams.
(16)
UNIT - IV
FIBER OPTICAL RECEIVERS
PART- A ( 2 marks)
1. Define diffusion length.
2. Define avalanche effect .
3. Define responsivity.
4. Define Quantum efficiency of photo detector.
5. Write the noise sources in the receiver section.
6.Define Quantum limit.
7.What are the desired features of photo detector.
8.A photo diode is constructed of GaAs which has a bandgap energy of 1.43Ev at 300k.
What is meant by long wavelength cutoff?
9.What are the benefits of trans impedance amplifier.
10.Define long wave length cutoff related photo diode.
11.What is meant by bulk dark current?
12.A photo diode has a capacitance of 6pf.Calculate the max load resistance which allows
an 8MHz post defection BW.
13. What is meant by impact ionization. In APD?
14.What is transit time of photo carriers?
15.What is meant by ionization rate?
16. Define avalanche multiplication?
17.Define S/N ratio of an optical receiver?What are the conditions are required
to achieve high S/N?
18.Define BER?
19.Define Extinction ratio?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
20. Define photo current?
21. What is p+ πpn+ reach through structure?
22.Define excess noise factor?
23. What is meant by Pre amplifier? What are the advantages of pre amplifier?
24.Whar are the draw backs of high impedance amplifier?
PART - B
1. Describe the working principle of PIN photo detector and explain the characteristics
of pin diode.
(16)
2. Explain with neat diagram, construction and working of APD. Compare photo
detectors.
(16)
3. Discuss the different noise sources and disturbances in the optical pulse detection
mechanism and derive the expression of S/N ratio.
(16)
4. a) Explain the fundamental receiver operation in optical communication.
(6)
b)Derive an expression for the bit error rate of an optical receiver.
(10)
5. Discuss the source of errors in optical receivers
(16)
6. The Quantum efficency of a RAPD is 80% for thr detection of radiation at 0.9um,
when incident optical power is 0.5uw.The output current from the device(after
avalance gain) is 11 uA. Determine avalanche multiplication factor?
(16)
UNIT - V
DIGITAL TRANSMISSION SYSTEM
PART- A ( 2 marks)
1. List out the requirements that are to be considered in analyzing a link
2. Differentiate link power budget and rise time budget.
3. What is SONET? How does it differ from SDH?
4. What are solitons?
5. What is meant by 'modal noise'?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
PART-B
1. Write notes on LINK POWER BUDGET.
(16)
2. Write notes on RISE TIME BUDGET.
(16)
3. Write notes on SONET.
(16)
4. List out the WDM components. Explain them briefly.
(16)
5. Discuss the principles, requirements and applications of WDM.
(16)
--
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ENGINEERING
QUESTION BANK
SUBJECT CODE
: EC1402
SEM / YEAR :
VII/ IV
SUBJECT NAME : OPTICAL COMMUNICATION
UNIT - I
INTRODUCTION TO OPTICAL FIBERS
PART- A ( 2 marks)
1. Among Microwaves and light waves which have high bit rate distance product?Why?
2. Mention the three advantages of optical fiber as waveguide over conventional
metallic waveguide?
3. What is meant by mode and index profile?
4. Mention the advantages of Graded Index fiber.
5. Write the expression for the refractive index in Graded index fiber.
6. Define Numerical Aperture of step index fiber.
7. Give the expression of the effective number of modes that are guided by a curved
multimode fiber of radius ' a'.
8. State Snells Law.
9. Define Critical angle?
10.Define TIR?
11.What is the need of Cladding?
12.Define core index difference.
13.Define refractive index?
14.What are leaky modes in optical fibers?
15.Define External reflection of light rays?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
16.What is meant by modes of waveguide?
17.Define V number?
18.What is relation between V number and power flow in cladding?
19.What is the fundamental parameter of SM fiber?
20.Give the relation between rays and modes?
21.What are the advantages and disadvantages of SM fiber?
22.What are the advantages and disadvantages of MM fiber?
23.Define skew rays and merdional rays?
24.Define cutoff conditions?
25.What is meant by Degenerate modes?
26.What is meant by linearly polarized modes?
27.Define MFD?
28.Define Bi refrigence and beat length?
29.A point source of light is 12cm below the surface of a large body of water (n=1.33).
What is the radius of the largest circle on the water surface through which the lights
can emerge?
30.Consider a parabolic index waveguide with n
1
=1.75,n
2
=1.677 and core radius 52um.
Calculate the numerical aperture at the axis and at a point 20um from the axis.
31.Why do we prefer step index single mode fiber for long distance communication?
32.Why do we use LP
01
mode for long distance communications?
33.What are three operating windows?
34.Alight ray is incident from glass to air. Calculate critical angle?
PART - B
1. What are Fiber modes? Explain mode theory for optical fiber in detail?
(16)
2. Compare SM fiber and Graded index fiber. Explain the requirements for fiber
materials?
(16)
3. Discuss the theory of GI fiber. Derive the expression for the numerical aperture of GI
fiber?
(16)
4. Derive an expression for number of modes propagating in GI fiber from the first
principle .
(16)
5. i) Mention the advantages of optical communication systems?
(8)
ii) Draw the elements of an optical communication systems?
(8)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
6. i) Discuss the propagation modes in SM fiber
(8)
ii)Briefly explain the evolution of fiber optic systems?
(8)
6. i)Compare the configurations of different types of fibers?
(8)
ii) Discuss the modes in Step index fiber?
(8)
7. i)Derive the wave equations for step index fiber and explain?
(8)
ii)Sketch and explain the electric field distributions of low order guided modes in
symmetrical slab waveguide?
(8)
8. A fiber has normalized frequency is 26.6 and wavelength is 1300nm.If the
radius of core is 25um.Compute numerical aperture?
(16)
9. a) A multimode step index fiber with core diameter of 80um and index difference of
1.5% at wavelength of 0.85um.If the refractive is 1.48,find normalized frequency and
no of modes?
(8)
b) Derive the expression for power flow in step index fiber?
(8)
10.a)Explain Linearly polarized modes?
(8)
b)The relative index difference in graded index fiber is 0.7% ,core refractive is
1.45.Find numerical aperture when index profile is triangular.
(8)
11 a).Derive modal equation.
(8)
b) Compare single and multimode fiber.
(8)
UNIT II
SIGNAL DEGRADATION OPTICAL FBERS
PART- A ( 2 marks)
1. An optical signal has lost 55% of its power after traversing 3.5 km of fiber. What is
the loss in dB/km of this fiber?
2. Define mode-field diameter.
3. What are the causes of absorption?
4. Define normalized propagation constant.
5. List the basic attenuation mechanisms in an optical fiber.
6. What is meant be mode coupling ? What causes it ?
7. Mention the two causes of intramodal dispersion.
8. Define fiber loss.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
9. What do you mean be polarization mode dispersion?
10.Commonly available single mode fibers have beat lengths in the range 10cm
11.Find the coupling loss for two fibers having core refractive index profiles α
E
=2.0
and α
R
=1.5
12.Define Raleigh Scattering loss.
13.Define Mie Scattering loss.
14.When the mean optical power launched into an 8 km length of fiber is 120 uw.
Determine the overall signal attenuation or loss in decibels.
15.How are micro bending losses reduced?
16.Distinguish intrinsic and extrinsic absorption.
17.Distinguish dispersion shifted and dispersion flattened fibers.
PART-B
1. What is meant by waveguide dispersion ? Derive the expression for the same. (16)
2. What is meant be material dispersion ? Derive the expression for the pulse
broadening due to material dispersion.
(16)
3. Discuss the signal distortion in single mode fibers.
(16)
4. Sketch the fundamental mode field in a curved optical wave guide and explain how
bending losses occur.
(16)
5. Explain with suitable diagrams the different mechanisms that contribute to attenuation
in optical fibers.
(16)
6. When the mean optical power launched into an 8km length of fiber is 120 uW, the
mean optical power at the fiber output is 3u W.
Determine
(1) Overall signal attenuation in dB/km and
(8)
(2) The overall signal attenuation for a 10km intervals, each giving an attenuation of
1dB.
(8)
7. Explain in detail mode coupling and design optimization of single mode fibers. (16)
8. Discuss in detail intermodal dispersion of multimode step index fiber with relevant
expression and diagrams.
(16)
9. What is mode coupling ? Discuss pulse broadening in GI fibers.
(16)
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
10.Discuss various kinds of losses that an optical signal might suffer while propagating
through fiber. Which is most important one? What is the effect of these losses on
light power and pulse shape?
(16)
11.A 6 km optical link consists of multimode step index with a core refractive index of 1.5
and a relative refractive index difference of 1%. Estimate the delay difference
between the slowest and fastest modes at the fiber output and the rms broadening
due to intermodal dispersion on the link. Also derive the expression involved in it.
(16)
UNIT III
FIBER OPTCAL SOURCES AND COUPLING
PART- A ( 2 marks)
1.
Define radiance.
2.
What is meant by " population inversion"?
3.
what is meant by heterojunction?
4.
What is meant by indirect band gap semiconductor material?
5.
Draw the three key transition processes involved in laser action.
6.
Give examples for direct and indirect semiconductor materials.
7.
Define internal quantum efficiency of an LED.
8.
Name few splicing methods in fiber optics.
9.
Compare LED and LASER.
10.
What so you mean by heterojunction ? Mention its advantages.
a. List the different types of mechanical misalignments that can occur between
two joined fibers.
b. Calculate the ratio of stimulated emission rata to the spontaneous emission
rate for a lamp operating at a temperature of 1000 K. Assume average
operating wavelength is 0.5um.
11.
Define lambertian pattern .
12.
Define FWHM.
13.
Define Modal or speckle noise.
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
14.
Define " Kinks".
15.
Define Mode partition noise.
16.
Define Lensing Schemes.
17.
Define Splicing ? What are types of Splicing.?
18.
What are the Characteristics of Light Source .
PART - B
1. Draw the two basic LED configurations and discuss the principle.
(16)
2. Discuss the principle of optical feedback and LASER oscillation.
(16)
3. Derive the threshold condition for LASER oscillation.
(16)
4. Explain various fiber splicing techniques.
(16)
5. Write technical notes on optical fiber connectors.
(16)
6. Discuss the laser diode structures and radiation patterns.(16)
7. Draw the structures of edge - emitting LED and surface emitting LED and
explain the operation.
(16)
8. Discuss the LASER diode principle , modes and threshold conditions.
(16)
9. Explain various types of fiber splicing techniques and fiber connectors.
(16)
10. Derive the threshold condition for LASER
(16)
11. Explain the laser action with neat diagrams.
(16)
12.a) A GaAs laser operating at 850 nm has a 500 um length and a refractive index
n = 3.7. What are the frequency and wavelength spacings?
(6)
b) With neat diagram explain the construction and working of high radiance surface
Emitting LED.
(10)
13. Discuss about modulation of laser diodes. Why thermoelectric coolers are used in
laser diodes.
(16)
14.Discuss in detail fiber splicing and connectors. Explain the operation principles of
WDM.
(16)
15.Draw and explain the LED structures based double hetero structure configuration.(16)
16.Discuss the principles of operation of laser diodes. What are the effects of temperature
on the performance of a laser diode?
(16)
17.Explain in different lensing schemes available to improve the power coupling
efficiency.
(16)
EC1402 OPTICAL COMMUNICATIONS
18.Explain the fiber splicing techniques with necessary diagrams.
(16)
UNIT - IV
FIBER OPTICAL RECEIVERS
PART- A ( 2 marks)
1. Define diffusion length.
2. Define avalanche effect .
3. Define responsivity.
4. Define Quantum efficiency of photo detector.
5. Write the noise sources in the receiver section.
6.Define Quantum limit.
7.What are the desired features of photo detector.
8.A photo diode is constructed of GaAs which has a bandgap energy of 1.43Ev at 300k.
What is meant by long wavelength cutoff?
9.What are the benefits of trans impedance amplifier.
10.Define long wave length cutoff related photo diode.
11.What is meant by bulk dark current?
12.A photo diode has a capacitance of 6pf.Calculate the max load resistance which allows
an 8MHz post defection BW.
13. What is meant by impact ionization. In APD?
14.What is transit time of photo carriers?
15.What is meant by ionization rate?
16. Define avalanche multiplication?
17.Define S/N ratio of an optical receiver?What are the conditions are required
to achieve high S/N?
18.Define BER?
19.Define Extinction ratio?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
20. Define photo current?
21. What is p+ πpn+ reach through structure?
22.Define excess noise factor?
23. What is meant by Pre amplifier? What are the advantages of pre amplifier?
24.Whar are the draw backs of high impedance amplifier?
PART - B
1. Describe the working principle of PIN photo detector and explain the characteristics
of pin diode.
(16)
2. Explain with neat diagram, construction and working of APD. Compare photo
detectors.
(16)
3. Discuss the different noise sources and disturbances in the optical pulse detection
mechanism and derive the expression of S/N ratio.
(16)
4. a) Explain the fundamental receiver operation in optical communication.
(6)
b)Derive an expression for the bit error rate of an optical receiver.
(10)
5. Discuss the source of errors in optical receivers
(16)
6. The Quantum efficency of a RAPD is 80% for thr detection of radiation at 0.9um,
when incident optical power is 0.5uw.The output current from the device(after
avalance gain) is 11 uA. Determine avalanche multiplication factor?
(16)
UNIT - V
DIGITAL TRANSMISSION SYSTEM
PART- A ( 2 marks)
1. List out the requirements that are to be considered in analyzing a link
2. Differentiate link power budget and rise time budget.
3. What is SONET? How does it differ from SDH?
4. What are solitons?
5. What is meant by 'modal noise'?
EC1402 OPTICAL COMMUNICATIONS
Kings College Of Engineering - Punalkulam
PART-B
1. Write notes on LINK POWER BUDGET.
(16)
2. Write notes on RISE TIME BUDGET.
(16)
3. Write notes on SONET.
(16)
4. List out the WDM components. Explain them briefly.
(16)
5. Discuss the principles, requirements and applications of WDM.
(16)
--
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பன்றிக் காய்ச்சல்
இந்த கட்டுரை ஒரு தமிழ் வெப்தளத்தில்
பதியப்பட்டிருந்தது, படித்தேன் இதை ஒவ்வொரு பன்றிக் காய்ச்சல் -
உலக நாடுகளையே இன்று கலங்கடித்துக் கொண்டிருக்கும் ஓர் கொடிய நோயின்
பெயர் இது.
கடந்த ஆண்டுகளில் பறவைக் காய்ச்சல் (சிக்குன் குன்யா) என்ற நோய் உலகளவில்
பல்லாயிரக் கணக்கான மக்களை வாட்டி வதைத்ததை போல், இந்த ஆண்டில் பன்றிக்
காய்ச்சல் நோய் உலக மக்களை பாடாய்படுத்திக் கொண்டிருக்கிறது.
முதன் முதலில் மெக்சிகோ நாட்டில் உருவானதாக கூறப்படும் இந்த கொடிய நோய்,
பின்னர் பல்வேறு நாடுகளுக்கும் பரவி, தற்போது இந்தியாவின் புனே நகரை
சேர்ந்த ரியா ஷேக் என்ற 14 வயது பள்ளி மாணவியின் உயிரை பறிக்கும்
அளவுக்கு பரவியுள்ளது. இதனால், ஒட்டுமொத்த இந்தியாவே அதிர்ச்சியடைந்துள்ள
சூழ்நிலையில், இந்நோய் பற்றிய கூடுதல் விபரங்களை அறிந்துக்கொள்வதும்,
அதிலிருந்து நம்மை நாமே வருமுன் காப்பதும் அவசியமாகிறது.
பன்றிக் காய்ச்சல் என்றால் என்ன?
பன்றிக் காய்ச்சல் (Swine flu) என்று அழைக்கப்படும் இந்த நோய், சளி,
இருமல், காய்ச்சல் ஆகியவற்றை ஏற்படுத்தும் புளூவைரஸின் ஓர் உட்பிரிவான H1
N1 என்ற வைரஸால் ஏற்படுகிறது. இது பன்றிகளின் சுவாச உறுப்பை தாக்கி,
கடுமையான காய்ச்சலை உருவாக்கி, படிப்படியாக உடல் உறுப்புகளை செயல் இழக்க
வைத்து இறுதியில் மரணத்தை ஏற்படுத்துகிறது. இந்த வைரஸ், பன்றிகளை
மட்டுமின்றி பறவைகள், குதிரை மற்றும் மனிதர்களையும் தாக்குகிறது.
கடந்த 1930ம் ஆண்டுகளில் முதன் முறையாக பன்றி இனங்களில் இந்நோய்
கண்டறியப்பட்டது. நோய்க்கான காரணம் குறித்து ஆய்வு செய்தபோது, இந்த வைரஸ்
மிக அரிதான ஓர் மரபு அணு தொகுதியை கொண்டிருந்ததை கண்டு ஆராய்ச்சியாளர்கள்
பெரும் ஆச்சரியமும், கடும் அதிர்ச்சியும் அடைந்தனர். அப்போதே இந்த
பன்றிக் காய்ச்சல் வைரஸ் மிக அபாயகரமானது என உலக சுகாதார நிறுவனம்
எச்சரிக்கை விடுத்தது. பின்னர் கடந்த 1965ல் ஐரோப்பாவிலும், 1976ம்
ஆண்டில் நியூஜெர்ஸியிலும் இந்நோய் கண்டறியப்பட்டது.
பன்றிக் காய்ச்சல் பரவும் முறை:
H1N1 வைரஸ், ஓர் பன்றியில் இருந்து மற்றொரு பன்றிக்கு வேகமாக பரவுகிறது.
நீண்டகால முயற்சிக்கு பின்னர் மனிதரை தாக்குதகிறது. ஆனால்,
மனிதரிடமிருந்து மற்றொரு மனிதருக்கு மிக எளிதில் தொற்றிக் கொள்கிறது.
பன்றிகள் வசிக்கும் இடம் அல்லது பன்றி பண்ணைகளில் பணிபுரிபவர்களுக்கு
இந்நோய் பரவி, அவர்களிடம் இருந்து மற்றவர்களுக்கு எளிதில் பரவுகிறது.
ஆனால், பன்றி இறைச்சி சாப்பிடுவதன் மூலமாக நோய் பரவ வாய்ப்புகள் இல்லை.
குளிர் மற்றும் பனிக்காலங்களிலுமே மிக அதிகமாக பரவுகிறது. குறிப்பாக இந்த
நோய்த் தொற்றுக்குள்ளாகி 5 முதல் 6 நாட்களில் பிறரையும் தொற்றுகிறது.
பன்றிக் காய்ச்சல் அறிகுறிகள்:
உடல் சூடாதல்,
உடல் பலவீனம்,
வலி,
தொண்டைப் புண்,
இருமல்,
பசியின்மை,
வயிற்றுப்போக்கு,
வாந்தி
போன்றவை பன்றிக் காய்ச்சலின் முக்கிய அறிகுறிகளாக கருதப்படுகின்றன.
பன்றிக் காய்ச்சல் பரவாமல் தடுக்கும் முறைகள்:
மக்கள் வசிக்கும் பகுதியில் பன்றிகள் நடமாடாமல் தடுக்க உரிய நடவடிக்கைகளை
எடுக்க வேண்டும்.
நோய் பாதிப்பு உள்ளவர்களை நேரடியாக தொட்டு பேசக்கூடாது. அவர்களிடமிருந்து
விலகியிருப்பது நல்லது.
பாதிக்கப்பட்டவர் அருகில் இருக்க நேர்ந்தால் வாய், மூக்கை மூடிக்கொள்ள
வேண்டும்.
கை, கால்களை நன்றாக சோப்பு போட்டு கழுவி சுத்தமாக வைத்திருக்க வேண்டும்.
பன்றிகளை வளர்ப்பவர்கள், பராமரிப்பவர்கள் மிகவும் கவனமாக இருக்க
வேண்டும்.
உலகளவில் பன்றிக் காய்ச்சல்:
கடந்த ஜூன் 11ம் தேதி உலக சுகாதார நிறுவனத்தால் கொள்ளை நோயாக
அறிவிக்கப்பட்ட இந்த பன்றிக் காய்ச்சல் நோய், உலகம் முழுவதும் வேகமாக
பரவி வருகிறது. இதனால், இந்நோயை கட்டுப்படுத்த அனைத்து நாடுகளின் விமான
நிலையங்களிலும் பன்றிக் காய்ச்சல் நோய் குறித்து மருத்துவப் பரிசோதனைகள்
நடைபெற்று வருகிறது.
பன்றிக் காய்ச்சல் நோய் பற்றிய பாதிப்புகளை உலக சுகாதார நிறுவனம்
அவ்வப்போது வெளியிட்டு வருகிறது. உலகம் முழுவதும் சுமார் 1 லட்சத்து 34
ஆயிரத்து 503 பேர் பாதிக்கப்பட்டுள்ளதாகவும், 816 பேர்
பலியாகியுள்ளதாகவும் அந்த மையம் தெரிவித்துள்ளது.
உலகளவில் மெக்சிகோ மற்றும் அமெரிக்கா போன்ற நாடுகள் இந்நோயால் அதிகம்
பாதிக்கப்பட்டுள்ள நிலையில், பன்றிக்காய்ச்சல் பாதிப்புள்ள நாடுகளுக்கு
செல்ல வேண்டாம் என பல நாடுகள் தங்களது நாட்டு மக்களை அறிவுறுத்தியுள்ளது.
இந்தியாவில் பன்றிக் காய்ச்சல்:
இந்தியாவில் கடந்த 2004ம் ஆண்டே டெல்லி, மிசோரம், மேற்கு வங்கம் போன்ற
மாநிலங்களில் இந்நோயின் அறிகுறிகள் தென்பட்டன. இதனால், இந்நோயால்
ஏற்படும் பாதிப்புகளை உணர்ந்திருந்த மருத்துவத் துறையினர், எச்1 என்1
வைரஸ் மனிதர்களை தாக்கும் முன்பே, பன்றிக் காய்ச்சல் நோயை
கட்டுப்படுத்திவிட்டனர்.
எனினும், இந்த ஆண்டின் ஆரம்பத்தில் இருந்து வெளிநாட்டுப் பயணிகள் மூலம்
இந்தியாவுக்குள்ளும் பன்றிக் காய்ச்சல் நோய் பரவ ஆரம்பித்தது.
மகாராஷ்டிராவில் அதிகப்பட்சமாக 135 பேரும், டெல்லியில் 109 பேரும்
பாதிக்கப்பட்டுள்ளனர். சென்னையில் 31 பேர் பாதிக்கப்பட்டுள்ளனர்.
இந்தியாவில் பன்றிக் காய்ச்சலால் பாதிக்கப்பட்டோரின் எண்ணிக்கை கடந்த 3ம்
தேதி நிலவரப்படி 574 ஆக உயர்ந்துள்ளது.
இந்நோய்க்கு புனே மாணவி ரியா ஷேக் பலியானதன் எதிரொலியாக, இந்தியாவில்
பன்றிக் காய்ச்சலை தடுக்க புதிய திட்டம் தீட்டப்பட்டு வருவதாகவும் மத்திய
சுகாதாரத்துறை அமைச்சர் குலாம்நபி ஆசாத் தெரிவித்துள்ளார்.
புனேவில் பன்றிக் காய்ச்சல்:
இந்தியாவில் பல்வேறு மாநிலங்களிலும் இந்நோய் பாதிப்பு ஏற்பட்ட போதிலும்,
மகாராஷ்டிர மாநிலத்திலுள்ள புனே நகரம் தான் பன்றிக் காய்ச்சல் நோயின்
தலைநகராக விளங்கி வருகிறது.
இங்குள்ள ஓர் பள்ளியை சேர்ந்த மாணவர்கள் சமீபத்தில் அமெரிக்க சுற்றுப்
பயணம் சென்று வந்ததாகவும், அவர்கள் மூலமாக பிற பள்ளி மாணவர்களுக்கும்
இந்நோய் தொற்றியதாகவும் கூறப்படுகிறது.
ஒரு கட்டத்தில் பள்ளி மாணவ, மாணவிகள் அதிகளவில் பாதிக்கப்பட்ட நிலையில்,
அங்குள்ள பல பள்ளிகளுக்கு விடுமுறை அளிக்கப்பட்டன.
இந்நிலையில், இந்தியாவில் பன்றிக் காய்ச்சலுக்கு முதல் பலியாக புனே நகரை
சேர்ந்த ரியா ஷேக் என்ற 14 வயது நிரம்பிய பள்ளி சநேற்று முன்தினம்
பலியானார். பெற்றோரின் கவனக்குறைவு மற்றும் மருத்துவர்கள் முன்கூட்டியே
நோயை கண்டறிந்து முறையாக சிகிச்சை அளிக்காதது போன்றவையே ரியாவின்
மரணத்துக்கு முக்கிய காரணமாக கருதப்படுகிறது.
நோய் தொற்றிய 20 தினங்களில் மாணவி ரியா, பன்றிக் காய்ச்சலுக்கு பலியாகி
இருப்பது மருத்துவ உலகையே அதிர்ச்சிக்குள்ளாக்கியுள்ளது.
தமிழகத்தில் பன்றிக் காய்ச்சல்:
பன்றிக் காய்ச்சல் நோயால் பாதிக்கப்பட்டோரின் எண்ணிக்கை தமிழகத்திலும்
நாளுக்கு நாள் அதிகரித்து வருவது. இந்நோயால் இதுவரை 35 பேர்
பாதிக்கப்பட்டுள்ளதாக தெரிகிறது.
புனே மாணவி ரியா பலியானதன் எதிரொலியாக, தமிழக அரசும் பன்றிக்காய்ச்சல்
நோய் ஒழிக்க தீவிரம் காட்டி வருகிறது. அதன்படி, பள்ளி மாணவ, மாணவிகளுக்கு
இதுகுறித்து விழிப்புணர்வு அளிக்கப்பட்டு வருகிறது. விமானப் பயணிகள்
மட்டுமின்றி, ரயில் மற்றும் கப்பல் மூலம் தமிழகம் வரும் பயணிகளுக்கும்
மருத்துவப் பரிசோதனை செய்ய திட்டமிடப்பட்டுள்ளது.
இதுதவிர, மும்பை, புனே நகரங்களுக்கு தமிழகத்தில் இருந்து யாரும் செல்ல
வேண்டாம் என்றும் தமிழக அரசு எச்சரிக்கை விடுத்துள்ளது.
தமிழகத்தில் சென்னை கிங்ஸ் இன்ஸ்டிடியூட், வேலூர் கிறிஸ்தவ மருத்துவக்
கல்லூரி ஆகியவற்றில் பன்றிக் காய்ச்சல் பற்றிய மருத்துவப் பரிசோதனை
நடத்தப்பட்டு வருகிறது.
சென்னை நகரில், தண்டையார் பேட்டை தொற்றுநோய் தடுப்பு மருத்துவமனை,
ராயப்பேட்டை அரசு மருத்துவமனை, ஸ்டான்லி அரசு மருத்துவமனை, கீழ்ப்பாக்கம்
அரசு மருத்துவமனை மற்றும் தண்டையார்பேட்டை பெரிபரல் மருத்துவமனை
போன்றவற்றில் பன்றிக் காய்ச்சலுக்கான மருத்துவச் சிகிச்சை அளிக்கப்பட்டு
வருகிறது.
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பதியப்பட்டிருந்தது, படித்தேன் இதை ஒவ்வொரு பன்றிக் காய்ச்சல் -
உலக நாடுகளையே இன்று கலங்கடித்துக் கொண்டிருக்கும் ஓர் கொடிய நோயின்
பெயர் இது.
கடந்த ஆண்டுகளில் பறவைக் காய்ச்சல் (சிக்குன் குன்யா) என்ற நோய் உலகளவில்
பல்லாயிரக் கணக்கான மக்களை வாட்டி வதைத்ததை போல், இந்த ஆண்டில் பன்றிக்
காய்ச்சல் நோய் உலக மக்களை பாடாய்படுத்திக் கொண்டிருக்கிறது.
முதன் முதலில் மெக்சிகோ நாட்டில் உருவானதாக கூறப்படும் இந்த கொடிய நோய்,
பின்னர் பல்வேறு நாடுகளுக்கும் பரவி, தற்போது இந்தியாவின் புனே நகரை
சேர்ந்த ரியா ஷேக் என்ற 14 வயது பள்ளி மாணவியின் உயிரை பறிக்கும்
அளவுக்கு பரவியுள்ளது. இதனால், ஒட்டுமொத்த இந்தியாவே அதிர்ச்சியடைந்துள்ள
சூழ்நிலையில், இந்நோய் பற்றிய கூடுதல் விபரங்களை அறிந்துக்கொள்வதும்,
அதிலிருந்து நம்மை நாமே வருமுன் காப்பதும் அவசியமாகிறது.
பன்றிக் காய்ச்சல் என்றால் என்ன?
பன்றிக் காய்ச்சல் (Swine flu) என்று அழைக்கப்படும் இந்த நோய், சளி,
இருமல், காய்ச்சல் ஆகியவற்றை ஏற்படுத்தும் புளூவைரஸின் ஓர் உட்பிரிவான H1
N1 என்ற வைரஸால் ஏற்படுகிறது. இது பன்றிகளின் சுவாச உறுப்பை தாக்கி,
கடுமையான காய்ச்சலை உருவாக்கி, படிப்படியாக உடல் உறுப்புகளை செயல் இழக்க
வைத்து இறுதியில் மரணத்தை ஏற்படுத்துகிறது. இந்த வைரஸ், பன்றிகளை
மட்டுமின்றி பறவைகள், குதிரை மற்றும் மனிதர்களையும் தாக்குகிறது.
கடந்த 1930ம் ஆண்டுகளில் முதன் முறையாக பன்றி இனங்களில் இந்நோய்
கண்டறியப்பட்டது. நோய்க்கான காரணம் குறித்து ஆய்வு செய்தபோது, இந்த வைரஸ்
மிக அரிதான ஓர் மரபு அணு தொகுதியை கொண்டிருந்ததை கண்டு ஆராய்ச்சியாளர்கள்
பெரும் ஆச்சரியமும், கடும் அதிர்ச்சியும் அடைந்தனர். அப்போதே இந்த
பன்றிக் காய்ச்சல் வைரஸ் மிக அபாயகரமானது என உலக சுகாதார நிறுவனம்
எச்சரிக்கை விடுத்தது. பின்னர் கடந்த 1965ல் ஐரோப்பாவிலும், 1976ம்
ஆண்டில் நியூஜெர்ஸியிலும் இந்நோய் கண்டறியப்பட்டது.
பன்றிக் காய்ச்சல் பரவும் முறை:
H1N1 வைரஸ், ஓர் பன்றியில் இருந்து மற்றொரு பன்றிக்கு வேகமாக பரவுகிறது.
நீண்டகால முயற்சிக்கு பின்னர் மனிதரை தாக்குதகிறது. ஆனால்,
மனிதரிடமிருந்து மற்றொரு மனிதருக்கு மிக எளிதில் தொற்றிக் கொள்கிறது.
பன்றிகள் வசிக்கும் இடம் அல்லது பன்றி பண்ணைகளில் பணிபுரிபவர்களுக்கு
இந்நோய் பரவி, அவர்களிடம் இருந்து மற்றவர்களுக்கு எளிதில் பரவுகிறது.
ஆனால், பன்றி இறைச்சி சாப்பிடுவதன் மூலமாக நோய் பரவ வாய்ப்புகள் இல்லை.
குளிர் மற்றும் பனிக்காலங்களிலுமே மிக அதிகமாக பரவுகிறது. குறிப்பாக இந்த
நோய்த் தொற்றுக்குள்ளாகி 5 முதல் 6 நாட்களில் பிறரையும் தொற்றுகிறது.
பன்றிக் காய்ச்சல் அறிகுறிகள்:
உடல் சூடாதல்,
உடல் பலவீனம்,
வலி,
தொண்டைப் புண்,
இருமல்,
பசியின்மை,
வயிற்றுப்போக்கு,
வாந்தி
போன்றவை பன்றிக் காய்ச்சலின் முக்கிய அறிகுறிகளாக கருதப்படுகின்றன.
பன்றிக் காய்ச்சல் பரவாமல் தடுக்கும் முறைகள்:
மக்கள் வசிக்கும் பகுதியில் பன்றிகள் நடமாடாமல் தடுக்க உரிய நடவடிக்கைகளை
எடுக்க வேண்டும்.
நோய் பாதிப்பு உள்ளவர்களை நேரடியாக தொட்டு பேசக்கூடாது. அவர்களிடமிருந்து
விலகியிருப்பது நல்லது.
பாதிக்கப்பட்டவர் அருகில் இருக்க நேர்ந்தால் வாய், மூக்கை மூடிக்கொள்ள
வேண்டும்.
கை, கால்களை நன்றாக சோப்பு போட்டு கழுவி சுத்தமாக வைத்திருக்க வேண்டும்.
பன்றிகளை வளர்ப்பவர்கள், பராமரிப்பவர்கள் மிகவும் கவனமாக இருக்க
வேண்டும்.
உலகளவில் பன்றிக் காய்ச்சல்:
கடந்த ஜூன் 11ம் தேதி உலக சுகாதார நிறுவனத்தால் கொள்ளை நோயாக
அறிவிக்கப்பட்ட இந்த பன்றிக் காய்ச்சல் நோய், உலகம் முழுவதும் வேகமாக
பரவி வருகிறது. இதனால், இந்நோயை கட்டுப்படுத்த அனைத்து நாடுகளின் விமான
நிலையங்களிலும் பன்றிக் காய்ச்சல் நோய் குறித்து மருத்துவப் பரிசோதனைகள்
நடைபெற்று வருகிறது.
பன்றிக் காய்ச்சல் நோய் பற்றிய பாதிப்புகளை உலக சுகாதார நிறுவனம்
அவ்வப்போது வெளியிட்டு வருகிறது. உலகம் முழுவதும் சுமார் 1 லட்சத்து 34
ஆயிரத்து 503 பேர் பாதிக்கப்பட்டுள்ளதாகவும், 816 பேர்
பலியாகியுள்ளதாகவும் அந்த மையம் தெரிவித்துள்ளது.
உலகளவில் மெக்சிகோ மற்றும் அமெரிக்கா போன்ற நாடுகள் இந்நோயால் அதிகம்
பாதிக்கப்பட்டுள்ள நிலையில், பன்றிக்காய்ச்சல் பாதிப்புள்ள நாடுகளுக்கு
செல்ல வேண்டாம் என பல நாடுகள் தங்களது நாட்டு மக்களை அறிவுறுத்தியுள்ளது.
இந்தியாவில் பன்றிக் காய்ச்சல்:
இந்தியாவில் கடந்த 2004ம் ஆண்டே டெல்லி, மிசோரம், மேற்கு வங்கம் போன்ற
மாநிலங்களில் இந்நோயின் அறிகுறிகள் தென்பட்டன. இதனால், இந்நோயால்
ஏற்படும் பாதிப்புகளை உணர்ந்திருந்த மருத்துவத் துறையினர், எச்1 என்1
வைரஸ் மனிதர்களை தாக்கும் முன்பே, பன்றிக் காய்ச்சல் நோயை
கட்டுப்படுத்திவிட்டனர்.
எனினும், இந்த ஆண்டின் ஆரம்பத்தில் இருந்து வெளிநாட்டுப் பயணிகள் மூலம்
இந்தியாவுக்குள்ளும் பன்றிக் காய்ச்சல் நோய் பரவ ஆரம்பித்தது.
மகாராஷ்டிராவில் அதிகப்பட்சமாக 135 பேரும், டெல்லியில் 109 பேரும்
பாதிக்கப்பட்டுள்ளனர். சென்னையில் 31 பேர் பாதிக்கப்பட்டுள்ளனர்.
இந்தியாவில் பன்றிக் காய்ச்சலால் பாதிக்கப்பட்டோரின் எண்ணிக்கை கடந்த 3ம்
தேதி நிலவரப்படி 574 ஆக உயர்ந்துள்ளது.
இந்நோய்க்கு புனே மாணவி ரியா ஷேக் பலியானதன் எதிரொலியாக, இந்தியாவில்
பன்றிக் காய்ச்சலை தடுக்க புதிய திட்டம் தீட்டப்பட்டு வருவதாகவும் மத்திய
சுகாதாரத்துறை அமைச்சர் குலாம்நபி ஆசாத் தெரிவித்துள்ளார்.
புனேவில் பன்றிக் காய்ச்சல்:
இந்தியாவில் பல்வேறு மாநிலங்களிலும் இந்நோய் பாதிப்பு ஏற்பட்ட போதிலும்,
மகாராஷ்டிர மாநிலத்திலுள்ள புனே நகரம் தான் பன்றிக் காய்ச்சல் நோயின்
தலைநகராக விளங்கி வருகிறது.
இங்குள்ள ஓர் பள்ளியை சேர்ந்த மாணவர்கள் சமீபத்தில் அமெரிக்க சுற்றுப்
பயணம் சென்று வந்ததாகவும், அவர்கள் மூலமாக பிற பள்ளி மாணவர்களுக்கும்
இந்நோய் தொற்றியதாகவும் கூறப்படுகிறது.
ஒரு கட்டத்தில் பள்ளி மாணவ, மாணவிகள் அதிகளவில் பாதிக்கப்பட்ட நிலையில்,
அங்குள்ள பல பள்ளிகளுக்கு விடுமுறை அளிக்கப்பட்டன.
இந்நிலையில், இந்தியாவில் பன்றிக் காய்ச்சலுக்கு முதல் பலியாக புனே நகரை
சேர்ந்த ரியா ஷேக் என்ற 14 வயது நிரம்பிய பள்ளி சநேற்று முன்தினம்
பலியானார். பெற்றோரின் கவனக்குறைவு மற்றும் மருத்துவர்கள் முன்கூட்டியே
நோயை கண்டறிந்து முறையாக சிகிச்சை அளிக்காதது போன்றவையே ரியாவின்
மரணத்துக்கு முக்கிய காரணமாக கருதப்படுகிறது.
நோய் தொற்றிய 20 தினங்களில் மாணவி ரியா, பன்றிக் காய்ச்சலுக்கு பலியாகி
இருப்பது மருத்துவ உலகையே அதிர்ச்சிக்குள்ளாக்கியுள்ளது.
தமிழகத்தில் பன்றிக் காய்ச்சல்:
பன்றிக் காய்ச்சல் நோயால் பாதிக்கப்பட்டோரின் எண்ணிக்கை தமிழகத்திலும்
நாளுக்கு நாள் அதிகரித்து வருவது. இந்நோயால் இதுவரை 35 பேர்
பாதிக்கப்பட்டுள்ளதாக தெரிகிறது.
புனே மாணவி ரியா பலியானதன் எதிரொலியாக, தமிழக அரசும் பன்றிக்காய்ச்சல்
நோய் ஒழிக்க தீவிரம் காட்டி வருகிறது. அதன்படி, பள்ளி மாணவ, மாணவிகளுக்கு
இதுகுறித்து விழிப்புணர்வு அளிக்கப்பட்டு வருகிறது. விமானப் பயணிகள்
மட்டுமின்றி, ரயில் மற்றும் கப்பல் மூலம் தமிழகம் வரும் பயணிகளுக்கும்
மருத்துவப் பரிசோதனை செய்ய திட்டமிடப்பட்டுள்ளது.
இதுதவிர, மும்பை, புனே நகரங்களுக்கு தமிழகத்தில் இருந்து யாரும் செல்ல
வேண்டாம் என்றும் தமிழக அரசு எச்சரிக்கை விடுத்துள்ளது.
தமிழகத்தில் சென்னை கிங்ஸ் இன்ஸ்டிடியூட், வேலூர் கிறிஸ்தவ மருத்துவக்
கல்லூரி ஆகியவற்றில் பன்றிக் காய்ச்சல் பற்றிய மருத்துவப் பரிசோதனை
நடத்தப்பட்டு வருகிறது.
சென்னை நகரில், தண்டையார் பேட்டை தொற்றுநோய் தடுப்பு மருத்துவமனை,
ராயப்பேட்டை அரசு மருத்துவமனை, ஸ்டான்லி அரசு மருத்துவமனை, கீழ்ப்பாக்கம்
அரசு மருத்துவமனை மற்றும் தண்டையார்பேட்டை பெரிபரல் மருத்துவமனை
போன்றவற்றில் பன்றிக் காய்ச்சலுக்கான மருத்துவச் சிகிச்சை அளிக்கப்பட்டு
வருகிறது.
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Friday, August 7, 2009
Enabling Hidden files And folders By using Registry editor
If your system is unable to view your hidden files and folders, even if you try to change the folder option to view hidden files, you system is affected by some malware or Trojans. To re enable the option to view hidden files, do as given below
Go to START Menu and click on Run
Type RegEdit and press Enter to run registry editor.
Navigate to the following registry key:
HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/windows/CurrentVersion/Explorer/Advanced/Folder/Hidden/SHOWALL
In the right side verify that the CheckedValue, value data is REG_DWORD type. If it’s not( such as belongs to REG_SZ), then delete the CheckedValue value data. If the CheckedValue has been delete, create a new DWORD(32 BIT)value and name it as CheckedValue.
Double click on CheckedValue and change its value data to 1(virus may change it to 0 or2)
Within the same registry key, verify that the Typevalue data is of REG_SZ type, and has the value data “radio”. If not set it to radio. Virus may change it to blank
Set the system to Show all hidden files and folders, and then check if hidden files are shown or not.
Some viruses may disable the registry editor. Here is the way to enable it.
Start/run
Enter GPEdit.msc and press Enter
Navigate to the following location: User Configuration /Administrative Templates /System/
In the settings panel, locate the Prevent access to registry editing tools option, and then double click o it to open the settings dialog. Select Disabled or Not Configured.
Click on ok button. Try to run regedit.exe, and if required restart the computer.
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Go to START Menu and click on Run
Type RegEdit and press Enter to run registry editor.
Navigate to the following registry key:
HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/windows/CurrentVersion/Explorer/Advanced/Folder/Hidden/SHOWALL
In the right side verify that the CheckedValue, value data is REG_DWORD type. If it’s not( such as belongs to REG_SZ), then delete the CheckedValue value data. If the CheckedValue has been delete, create a new DWORD(32 BIT)value and name it as CheckedValue.
Double click on CheckedValue and change its value data to 1(virus may change it to 0 or2)
Within the same registry key, verify that the Typevalue data is of REG_SZ type, and has the value data “radio”. If not set it to radio. Virus may change it to blank
Set the system to Show all hidden files and folders, and then check if hidden files are shown or not.
Some viruses may disable the registry editor. Here is the way to enable it.
Start/run
Enter GPEdit.msc and press Enter
Navigate to the following location: User Configuration /Administrative Templates /System/
In the settings panel, locate the Prevent access to registry editing tools option, and then double click o it to open the settings dialog. Select Disabled or Not Configured.
Click on ok button. Try to run regedit.exe, and if required restart the computer.
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Nokia Code function
*3370# This Nokia code activates Enhanced Full Rate Codec (EFR) - Your Nokia cell phone uses the best sound quality but talk time is reduced my approx. 5%
#3370# Deactivate Enhanced Full Rate Codec (EFR)
*#4720# Activate Half Rate Codec - Your phone uses a lower quality sound but you should gain approx 30% more Talk Time
*#4720# With this Nokia code you can deactivate the Half Rate Codec
*#0000# Displays your phones software version, 1st Line : Software Version, 2nd Line : Software Release Date, 3rd Line : Compression Type
*#9999# Phones software version if *#0000# does not work
*#06# For checking the International Mobile Equipment Identity (IMEI Number)
#pw+1234567890+1# Provider Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+2# Network Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+3# Country Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+4# SIM Card Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
*#147# This lets you know who called you last (Only vodofone)
*#1471# Last call (Only vodofone)
*#21# This phone code allows you to check the number that "All Calls" are diverted to
*#2640# Displays phone security code in use
*#30# Lets you see the private number
*#43# Allows you to check the "Call Waiting" status of your cell phone.
*#61# Allows you to check the number that "On No Reply" calls are diverted to
*#62# Allows you to check the number that "Divert If Unreachable (no service)" calls are diverted to
*#67# Allows you to check the number that "On Busy Calls" are diverted to
*#67705646# Phone code that removes operator logo on 3310 & 3330
*#73# Reset phone timers and game scores
*#746025625# Displays the SIM Clock status, if your phone supports this power saving feature "SIM Clock Stop Allowed", it means you will get the best standby time possible
*#7760# Manufactures code
*#7780# Restore factory settings
*#8110# Software version for the nokia 8110
*#92702689# Displays - 1.Serial Number, 2.Date Made, 3.Purchase Date, 4.Date of last repair (0000 for no repairs), 5.Transfer User Data. To exit this mode you need to switch your phone off then on again
*#94870345123456789# Deactivate the PWM-Mem
**21*number# Turn on "All Calls" diverting to the phone number entered
**61*number# Turn on "No Reply" diverting to the phone number entered
**67*number# Turn on "On Busy" diverting to the phone number entered
12345 This is the default security code
press and hold # Lets you switch between lines
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#3370# Deactivate Enhanced Full Rate Codec (EFR)
*#4720# Activate Half Rate Codec - Your phone uses a lower quality sound but you should gain approx 30% more Talk Time
*#4720# With this Nokia code you can deactivate the Half Rate Codec
*#0000# Displays your phones software version, 1st Line : Software Version, 2nd Line : Software Release Date, 3rd Line : Compression Type
*#9999# Phones software version if *#0000# does not work
*#06# For checking the International Mobile Equipment Identity (IMEI Number)
#pw+1234567890+1# Provider Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+2# Network Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+3# Country Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
#pw+1234567890+4# SIM Card Lock Status. (use the "*" button to obtain the "p,w" and "+" symbols)
*#147# This lets you know who called you last (Only vodofone)
*#1471# Last call (Only vodofone)
*#21# This phone code allows you to check the number that "All Calls" are diverted to
*#2640# Displays phone security code in use
*#30# Lets you see the private number
*#43# Allows you to check the "Call Waiting" status of your cell phone.
*#61# Allows you to check the number that "On No Reply" calls are diverted to
*#62# Allows you to check the number that "Divert If Unreachable (no service)" calls are diverted to
*#67# Allows you to check the number that "On Busy Calls" are diverted to
*#67705646# Phone code that removes operator logo on 3310 & 3330
*#73# Reset phone timers and game scores
*#746025625# Displays the SIM Clock status, if your phone supports this power saving feature "SIM Clock Stop Allowed", it means you will get the best standby time possible
*#7760# Manufactures code
*#7780# Restore factory settings
*#8110# Software version for the nokia 8110
*#92702689# Displays - 1.Serial Number, 2.Date Made, 3.Purchase Date, 4.Date of last repair (0000 for no repairs), 5.Transfer User Data. To exit this mode you need to switch your phone off then on again
*#94870345123456789# Deactivate the PWM-Mem
**21*number# Turn on "All Calls" diverting to the phone number entered
**61*number# Turn on "No Reply" diverting to the phone number entered
**67*number# Turn on "On Busy" diverting to the phone number entered
12345 This is the default security code
press and hold # Lets you switch between lines
--
Sent on a phone using T9space.com
Google Search Tricks
Google search has been a blessing for developers, not only devlopers, bloggers, surfers and i guess everyone who is using the immense power of internet. They are the best in the business with their superb algorithms. Google search has some hidden easter eggs through which one can utilise the power of Google in a fun rather tricky way.
So here we go with a bunch of amazing tricks:
EBooks,EMusic,EMovies with Google:
Do you wanna download any pdf file, word document or mp3 file? Google can be the first place to look forward to, isn’t it? You must be wondering what could be the trick in that, well an enormous amount of free downloadable files can be easily accessed at Open Web Directories. Its like turning Google into Napster of 2000, isn’t it VOW !!
So here is the tricky url syntax:
-inurl:(htm|html|php) intitle:”index of” +”last modified” +”parent directory” +description +size +(your choice) “name”
“your choice” can be either of the following file types:
-> wma|mp3 for Music
-> pdf|doc for Ebooks
-> mpg|wmv for Videos
and “name” can be any specific music file, movie or book, you are looking for.
For example:
-inurl:(htm|html|php) intitle:”index of” +”last modified” +”parent directory” +description +size +(wma|mp3) “Shakira”
This is a Google search string for searching open web directories containing downloadable Shakira music files.
Ofcourse, you can always bookmark the search result for future use. Don’t worry, just enjoy !!
Lots of free downloadable stuff with Google:
Haven’t you fed up with searching for free wallpapers, stock images or social sites and getting nothing out of the search results??? Have your ever thought, why this happen when you have made right search queries, The only possible answer to this can be the most popular and most likable word “free”, it attracts spams. Anyways, don’t be upset, we do have a trick for that also. All you have to do is to direct Google to numerous available social media sites which have an active community of users who have already reviewed and ranked various “free” items that may interst you.
So here are some tricky queries:
-> site:del.icio.us free “stock images”
-> site:netscape.com free “ringtones”
-> site:digg.com free “desktop wallpaper”
-> site:reddit.com free “wordpress templates”
-> site:stumbleupon.com free icons
Have fun with your favourite free stuff!!
Free Anonymous Web Proxies with Google:
All you have to do is look through the search results returned by the queries below, find a proxy that works, and enter in the URL of the site you want to browse anonymously.
Use the following query and enjoy:
-> inurl:”nph-proxy.cgi” “start using cgiproxy”
-> inurl:”nph-proxy.cgi” “Start browsing through this CGI-based proxy”
Search only Faces with Google Image Search:
You can use this trick on Google Image search to filter the search results so that they include only images of people. This search can be performed just by appending the string &imgtype=face at the end of the URL address after you perform a standard Google Image search.
Tricks4fun.com
POSTED BY TAIJU AT 6:27 AM 0 COMMENTS
LABELS: INTERNET TRICKS
Boost your Internet Connection speed up to 200
Wednesday, July 15, 2009
Internet Cyclone - Boost your Internet Connection speed up to 200% !!!
As you all know the internet speed of dial up is very low and beowsing through it is a time consuming process .It can be avoided by using Internet speed boosters
there are lot of speed boosters available, in that Internet_Cyclone is very good and it have simple user interface
Is a powerful, easy-to-use, Internet Optimizer for Windows 95, 98, ME, NT, 2000 and XP designed to automatically optimize your Windows settings which will boost your Internet connection speed
up to 200%. Internet Cyclone is compatible with all modems and high-speed LAN, ISDN, CABLE, DSL, T1 or other connections. This software will still be useful to you after
upgrading your internet connection.
--
Sent on a phone using T9space.com
So here we go with a bunch of amazing tricks:
EBooks,EMusic,EMovies with Google:
Do you wanna download any pdf file, word document or mp3 file? Google can be the first place to look forward to, isn’t it? You must be wondering what could be the trick in that, well an enormous amount of free downloadable files can be easily accessed at Open Web Directories. Its like turning Google into Napster of 2000, isn’t it VOW !!
So here is the tricky url syntax:
-inurl:(htm|html|php) intitle:”index of” +”last modified” +”parent directory” +description +size +(your choice) “name”
“your choice” can be either of the following file types:
-> wma|mp3 for Music
-> pdf|doc for Ebooks
-> mpg|wmv for Videos
and “name” can be any specific music file, movie or book, you are looking for.
For example:
-inurl:(htm|html|php) intitle:”index of” +”last modified” +”parent directory” +description +size +(wma|mp3) “Shakira”
This is a Google search string for searching open web directories containing downloadable Shakira music files.
Ofcourse, you can always bookmark the search result for future use. Don’t worry, just enjoy !!
Lots of free downloadable stuff with Google:
Haven’t you fed up with searching for free wallpapers, stock images or social sites and getting nothing out of the search results??? Have your ever thought, why this happen when you have made right search queries, The only possible answer to this can be the most popular and most likable word “free”, it attracts spams. Anyways, don’t be upset, we do have a trick for that also. All you have to do is to direct Google to numerous available social media sites which have an active community of users who have already reviewed and ranked various “free” items that may interst you.
So here are some tricky queries:
-> site:del.icio.us free “stock images”
-> site:netscape.com free “ringtones”
-> site:digg.com free “desktop wallpaper”
-> site:reddit.com free “wordpress templates”
-> site:stumbleupon.com free icons
Have fun with your favourite free stuff!!
Free Anonymous Web Proxies with Google:
All you have to do is look through the search results returned by the queries below, find a proxy that works, and enter in the URL of the site you want to browse anonymously.
Use the following query and enjoy:
-> inurl:”nph-proxy.cgi” “start using cgiproxy”
-> inurl:”nph-proxy.cgi” “Start browsing through this CGI-based proxy”
Search only Faces with Google Image Search:
You can use this trick on Google Image search to filter the search results so that they include only images of people. This search can be performed just by appending the string &imgtype=face at the end of the URL address after you perform a standard Google Image search.
Tricks4fun.com
POSTED BY TAIJU AT 6:27 AM 0 COMMENTS
LABELS: INTERNET TRICKS
Boost your Internet Connection speed up to 200
Wednesday, July 15, 2009
Internet Cyclone - Boost your Internet Connection speed up to 200% !!!
As you all know the internet speed of dial up is very low and beowsing through it is a time consuming process .It can be avoided by using Internet speed boosters
there are lot of speed boosters available, in that Internet_Cyclone is very good and it have simple user interface
Is a powerful, easy-to-use, Internet Optimizer for Windows 95, 98, ME, NT, 2000 and XP designed to automatically optimize your Windows settings which will boost your Internet connection speed
up to 200%. Internet Cyclone is compatible with all modems and high-speed LAN, ISDN, CABLE, DSL, T1 or other connections. This software will still be useful to you after
upgrading your internet connection.
--
Sent on a phone using T9space.com
Monday, August 3, 2009
Nokia mobile tips, tricks
Free Nokia mobile tips, tricks, secrets & downloads
All the tips and tricks provided by Hidden Tricks is free and its not necessary to sign up also.
If you want to receive our latest tips & tricks in your mailbox, you can sunscribe for our Newsletter for free.
To check Nokia mobile or cellphones IMEI (International Mobile Equipment Identity)
On the main screen type *#06#
Information you get from the IMEI (International Mobile Equipment Identity)
XXXXXX XX XXXXXX X
TAC FAC SNR SP
TAC = Type approval code of your nokia Mobile
FAC = Final assembly code of your cellphone
SNR = Serial number of your nokia Phone
SP = Spare
Other secret tricks for Nokia mobile or cellphone
To check the phones Software revision for Nokia Mobile.
On the main screen type *#0000#
To enter in the secret menu in Nokia Phone.
On the main screen type *#92702689# [*#war0anty#]
It will take you to a secret menu where you may find some of the information below:
1. Displays Serial Number.
2. Displays the Month and Year of Manufacture
3. Displays (if there) the date where the phone was purchased (MMYY)
4. Displays the date of the last repair - if found (0000)
5. Shows life timer of phone (time passes since last start)
To restore Factory Settings for Nokia mobile
*#7780# reset to factory settings.
Taking picture without getting noticed.
Turn on/off the "click" sound made by the camera by selecting the 'Silent' profile or by turning warning tones on/off.
Hiding your Mobile/ Cellphone Number
Go to: Menu > Tools > Settings > Call > Send My Caller ID >
'Yes', 'No' or 'Set By Network' to follow the default settings of your home network.
It works only with very few network who provide you facility of “Private Number”
Speed Dialing From Simcard contact (not stored in mobile phonebook)
Type number followed by # then call.
Example: 1# or 2# or 21#
--
Sent on a phone using T9space.com
All the tips and tricks provided by Hidden Tricks is free and its not necessary to sign up also.
If you want to receive our latest tips & tricks in your mailbox, you can sunscribe for our Newsletter for free.
To check Nokia mobile or cellphones IMEI (International Mobile Equipment Identity)
On the main screen type *#06#
Information you get from the IMEI (International Mobile Equipment Identity)
XXXXXX XX XXXXXX X
TAC FAC SNR SP
TAC = Type approval code of your nokia Mobile
FAC = Final assembly code of your cellphone
SNR = Serial number of your nokia Phone
SP = Spare
Other secret tricks for Nokia mobile or cellphone
To check the phones Software revision for Nokia Mobile.
On the main screen type *#0000#
To enter in the secret menu in Nokia Phone.
On the main screen type *#92702689# [*#war0anty#]
It will take you to a secret menu where you may find some of the information below:
1. Displays Serial Number.
2. Displays the Month and Year of Manufacture
3. Displays (if there) the date where the phone was purchased (MMYY)
4. Displays the date of the last repair - if found (0000)
5. Shows life timer of phone (time passes since last start)
To restore Factory Settings for Nokia mobile
*#7780# reset to factory settings.
Taking picture without getting noticed.
Turn on/off the "click" sound made by the camera by selecting the 'Silent' profile or by turning warning tones on/off.
Hiding your Mobile/ Cellphone Number
Go to: Menu > Tools > Settings > Call > Send My Caller ID >
'Yes', 'No' or 'Set By Network' to follow the default settings of your home network.
It works only with very few network who provide you facility of “Private Number”
Speed Dialing From Simcard contact (not stored in mobile phonebook)
Type number followed by # then call.
Example: 1# or 2# or 21#
--
Sent on a phone using T9space.com
Mobile tricks
format nokia
s40,s80,e series
*#7780#
s30,s60,n series
*#7370#
--
Sent on a phone using T9space.com
s40,s80,e series
*#7780#
s30,s60,n series
*#7370#
--
Sent on a phone using T9space.com
Mobile tricks
WaNt To PlAy uR SoNy ErriCsSoN Mobile's FM WiThOuT HeAdPhOnE ?
JusT EnTeR ThiS CoDe On Ur MoBiLe ScReeN
*#**372#
SeLeCT RaDiO ON/OFF
just try.........
--
Sent on a phone using T9space.com
JusT EnTeR ThiS CoDe On Ur MoBiLe ScReeN
*#**372#
SeLeCT RaDiO ON/OFF
just try.........
--
Sent on a phone using T9space.com
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