EC6702 Optical Communication and Networks Important questions

EC6702 Optical Communication and Networks Important questions Regulation 2013 Anna University free download. Optical Communication and Networks EC6702 Important questions pdf free download.

Sample EC6702 Optical Communication and Networks Important questions:

1. What are the limitations of optical fiber communication systems?

 Optical fiber is made up of glass. Because of the impurities present with the
fiber It results in absorption, which leads to loss of light in the optical fiber.
 It is costly.
 Maximum limitation of the bandwidth of the signals can be carried by the
fiber due to spreading of pulse.

2. What is the necessity of cladding for an optical fiber?

The necessity of cladding for an optical fiber is
 To avoid leakage of light from the fiber
 To avoid mechanical strength for the fiber
 To protect core from scratches and other mechanical damages. (EC6702 Optical Communication and Networks Important questions)

3. List the advantages of mono-mode fiber.

The advantages of mono-mode fiber are
 No internal dispersion
 Information capacity of single mode fiber is large.

4. Define – Acceptance Angle

The maximum angle Фmax with which a ray of light can enter rough the entrance
end of the fibre and still be totally internally reflected is called acceptance angle
of the fiber. (EC6702 Optical Communication and Networks Important questions)

5. List the uses of optical fiber.

The uses of optical fibers are as follows
 To act as light source at the inaccessible places
 To transmit the optical images. (example: endoscopy)To act as sensors
to do mechanical, electrical and magnetic measurements
 To transmit the information which are in the form of coded signals
of the telephone communications, computer data etc.

(EC6702 Optical Communication and Networks Important questions)

Subject Name	Optical Communication and Networks
Subject code	EC6702
Regulation	2013

EC6702 Optical Communication and Networks Important questions click here to download

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EC6701 RF AND MICROWAVE ENGINEERING Important questions

EC6701 RF and microwave engineering Important questions regulation 2013 anna university free download. RF and microwave engineering EC6701 Important questions pdf free download.

Sample EC6701 RF and microwave engineering Important questions:

TWO MARK QUESTIONS-ANSWERS

1. Define s-matrix

In a microwave junction there is intersection of three or more
components.There will be an output port ,in addition there may be reflection from
the junction of other ports.Totally there may be many combinations,these are
represented easily using a matrix called S matrix.

2 What are the .Properties of s-matrix?

It possess symmetric property sij =sji
It possess unitary property [s][s]*=[i] (EC6701 RF and microwave engineering Important questions)

3. Why is s-matrix used in MW analysis?

S matrix is used in MW analysis to overcome the problems which occurs when
H,Y,&Z parameters are used in high frequencies.
Equipment is not readily available to measure total voltage &total current at
the ports of the network.
Short and open circuits are difficult to achieve over a broad band of
frequencies.
Active devices,such as power transistor &tunnel diodes,frequently won‟t
have stability for a short or open circuit.

4. Give ABCD matrix for a two port network

V1=A B V2
I1 C D -I2

5. What is ABCD matrix?

ABCD matrix is a transmission matrix. These parameters express voltage and
current at output in terms of those at input port.
V1=AV2-BI2
I1=CV2-DI2 (EC6701 RF and microwave engineering Important questions)

6. What are the advantages of ABCD matrix?

They are used in power transmission lines.
They are very helpful in the case of cascade networks.

16 mark questions (EC6701 RF and microwave engineering Important questions)

1.Explain in detail about 2-cavity klystron amplifier.

2. Explain about the reflex klystron.

3. Explain about TWT amplifiers.

4. Explain about magnetron oscillator.

5. Numerical problems.
-calculation of output voltage, power,efficiency for 2-cavity klystron amplifier, reflex klystron,magnetron,TWTamplifiers.

6.What are the properties of scattering matrix for a lossless junction?

7.What are ferrites devices.Explain in detail the different ferrite devices

(EC6701 RF and microwave engineering Important questions)

Subject Name	RF and microwave engineering
Subject code	EC6701
Regulation	2013

EC6701 RF and microwave engineering Important questions click here to download

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EC6503 Transmission Lines and Wave Guides Important questions

EC6503 Transmission Lines and Wave Guides Important questions Regulation 2013 Anna University free download. Transmission Lines and Wave Guides EC6503 Important questions pdf free download.

Sample EC6503 Transmission Lines and Wave Guides Important questions:

Unit I

1. Discuss in detail about inductance loading of telephone cables and derive the attenuation constant, phase constant and velocity of signal transmission for the uniformly loaded cable

2. Explain in detail about the reflection on a line not terminated in its characteristics impedance. (ec6503 transmission lines and wave guides important questions)

3. A distortion less transmission line has attenuation constant α=1.15×10ˉᶟ Np/m, and capacitance of 0.01 n F/m. the characteristic resistance L/C=50Ω find the resistance inductance and conductance per more of the line.

4. A transmission line operating at 500 MHz has Z₀=80Ω, α= 0.04 Np/m, β=1.5 rad/m. Find the line parameter series resistance (R Ω/m), series inductance (L H/m), shunt conductance (G mho/m) and capacitance between conductors (C F/m). (ec6503 transmission lines and wave guides important questions)

5. Derive expression for the attenuation and phase constant of transmission line in constant R,L,G and C.

6. Draw the L-type equivalent circuit model of a two-conductor transmission line and derive the transmission line equations.

7. discuss the theory of open and short circuited lines with voltage and current distribution diagram and also get the input impedance expression.

8. Derive the expression for the input impedance of a transmission line Hence obtain the input impedance for a loss less line (ec6503 transmission lines and wave guides important questions)

9. A transmission line operating at 10⁶ rad/s has α= 8 d B/m, β= 1 rad/m. and z₀= 60+ j40ohms, and is 2meter long. The line is connected to a source of 10 v, Zg=40ohms and terminated by a load of 20 + j50ohms. Determine the current at the middle of the line.

Unit II EC6503 Transmission Lines and Wave Guides Important questions

1. Explain the application of smith chart A 30 m long loss less transmission line with Z0=50ohms operating at 2 MHz is terminated with a load ZL=60+j40ohms if U=0.6C find the reflection coefficient y, the standing wave ratios and the input impedance

2. Derive equation of attenuation constant and phase constant of transmission line in terms of line constants R, L, C and G and explain the significance of reflection coefficient and insertion loss (ec6503 transmission lines and wave guides important questions)

3. Derive the expression that permit easy measurement of power flow on a line of negligible losses

Subject Name	Transmission Lines and Wave Guides
Subject Code	EC6503
Regulation	2013

EC6503 Transmission Lines and Wave Guides Important questions click here to download

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EC6502 Principles of Digital Signal Processing Important questions

EC6502 Principles of Digital Signal Processing Important questions Regulation 2013 Anna University free download. Principles of Digital Signal Processing EC6502 Important questions pdf free download.

Sample EC6502 Principles of Digital Signal Processing Important questions:

Unit 1 EC6502 Principles of Digital Signal Processing Important questions

1. Find the 8-point DFT of x(n)={1,-1,1,-1,0,0,0,0} using Radix-2 DIT-FFT

2. Compute the 8-point DFT of equation x(n)=n2+1 using Radix-2 DIF-FFT 0 ≤ n ≤ N-1

3. With appropriate diagrams describe (i) overlap-save method,(ii)overlap-add method.

4. Explain Radix-2 DIF-FFT algorithm. Compare it with DIT-FFT algorithms.

5. Summarize the properties of DFT with proof.

Unit II EC6502 Principles of Digital Signal Processing Important questions

1. Design a digital butterworth filter satisfying constraints
0.707≤|H ()| ≤1, 0≤≤π/2
|H ()| ≤0.2, 3π/4 ≤≤π with T=0.1 sec using bilinear transformation

2. Design a digital Chebyshev filter satisfying constraints 0.707≤|H ()| ≤1, 0≤≤π/2 ; |H ()| ≤0.2, 3π/4
≤≤π with T=1 sec using bilinear transformation

3. Explain the bilinear transform method of IR filter design. What is warping effect? Explain the poles and zeros mapping procedure clearly. (ec6502 principles of digital signal processing Important questions)

4. Convert the following analog transfer function into digital using impulse invariant mapping and Bilinear mapping with T=1 sec.

5. Explain in detail about the steps involved in the design of IIR filter using bilinear transformation.

Unit III EC6502 Principles of Digital Signal Processing Important questions

1. Design a Linear phase FIR band pass filter to passing frequencies in the range of 0.4 π to 0.6 π rad/sample by taking 7 samples of hanning window sequence

2. Design an FIR low pass digital filter by using the frequency sampling method for the following specifications
Cutoff frequency =1500 Hz
Sampling frequency =15000 Hz
Order of filter N=10
Filter length L=N+1 =11 (ec6502 principles of digital signal processing Important questions)

3. Design a digital FIR band pass filter with lower cut off frequency 2000Hz and upper cut off frequency
3200 Hz using Hamming window of length N = 7. Sampling rate is 10000Hz

4. Explain the designing of FIR filters using windows

5. Determine the coefficients {h(n)} of a linear phase FIR filter of length M = 15 which has a symmetric unit sample response and a frequency response that satisfies the condition

Subject Name	Principles of Digital Signal Processing
Subject Code	EC6502
Regulation	2013

EC6502 Principles of Digital Signal Processing Important questions click here to download

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EC6501 Digital Communication Important questions

EC6501 Digital Communication Important questions regulation 2013 Anna University free download. Digital Communication EC6501 Important questions pdf free download.

Sample EC6501 Digital Communication Important questions:

Part A 2 marks 

1. What is inter symbol interference in baseband binary PAM systems?

In baseband binary PAM, symbols are transmitted one after another. These symbols are separated by sufficient time durations. The transmitter, channel and receiver acts as a filter to this baseband data. Because of the filtering characteristics, transmitted PAM pulses are spread in time.

2. What are eye pattern? (ec6501 digital communication important questions)

Eye pattern is used to study the effect of ISI in baseband transmission.
1. Width of eye opening defines the interval over which the received wave can be sampled without error from ISI.
2. The sensitivity of the system to timing error is determined by the rate of closure of the eye as the sampling
time is varied. (ec6501 digital communication important questions)
3. Height of the eye opening at sampling time is called margin over noise.

3. How is eye pattern obtained on the CRO?

Eye pattern can be obtained on CRO by applying the signal to one of the input channels and given an external trigger of 1/Tb Hz. This makes one sweep of beam equal to Tb seconds.

4. What is correlative coding?

Correlative level coding is used to transmit a baseband signal with the signaling rate of 2Bo over the channel of bandwidth Bo. This is made physically possible by allowing ISI in the transmitted in controlled manner. This ISI is known to receiver. The correlative coding is implemented by duo binary signaling and modified duo
binary signaling. (ec6501 digital communication important questions)

5. Define Duo binary baseband PAM system.

Duo binary encoding reduces the maximum frequency of the baseband signal. The word duo means to double the transmission capacity of the binary system. Let the PAM signal ak represents kth bit. Then the encoder the new waveform as
Ck =ak + ak-1 Thus two successive bits are added to get encoded value of the kth bit. Hence Ck becomes a correlated signal even though ak is not correlated. This introduces intersymbol interference in the controlled manner to reduce
the bandwidth. (ec6501 digital communication important questions)

6. What are the three broad types of synchronization?

1. Carrier synchronization
2. Symbol & Bit synchronization
3. Frame synchronization. (ec6501 digital communication important questions)

Subject Name	Digital Communication
Subject Code	EC6501
Regulation	2013

EC6501 Digital Communication Important questions click here to download

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EC6304 Electronic Circuits 1 Important questions

EC6304 Electronic Circuits 1 Important questions Regulation 2013 Anna University free download. Electronic Circuits 1 Important questions EC6304 pdf free download.

Sample EC6304 Electronic Circuits 1 Important questions:

Part A 2 MARKS

1. Define noise

Noise is an unwanted electrical signal which gets added tom a transmitted signal
when it is travelling towards the receiver

2. Define noise figure (EC6304 Electronic Circuits 1 Important questions)

Noise figure is a figure of merit and used to indicate how much the signal to noise
ratio gets degraded as a signal passes through a series of circuits

3. What is meant by analog communication system?

The modulation systems or techniques in which one of the characteristics of the
carrier is changed in proportion with the instantaneous value of modulating signal
is called analog communication system.

4. Define modulation (EC6304 Electronic Circuits 1 Important questions)

Modulation is defined as changing the characteristics of the carrier signal with
respect to the instantaneous change in message signal.

5. What are the needs for modulation

In order to carry the low frequency message signal to a longer distance, the high
frequency carrier signal is combined with it.
a) Reduction in antenna height
b) Long distance communication
c) Ease of radiation
d) Multiplexing
e) Improve the quality of reception
f) Avoid mixing up of other signals

6. What are the advantages of Analog communications (EC6304 Electronic Circuits 1 Important questions)

Transmitters and Receivers are simple
Low bandwidth requirement FDM can be used

7. What are the disadvantages of analog communication?

Noise affects the signal quality
It is not possible to separate noise and signal
Repeaters can’t be used between transmitters and receivers
Coding is not possible
It is not suitable for the transmission of secret information (EC6304 Electronic Circuits 1 Important questions)

Subject Name	Electronic Circuits 1
Subject Code	EC6304
Regulation	2013

EC6304 Electronic Circuits 1 Important questions click here to download

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EC6303 Signals and Systems Important questions

EC6303 Signals and Systems Important questions Regulation 2013 Anna University free download. Signals and Systems EC6303 Important questions pdf free download.

Sample EC6303 Signals and Systems Important questions:

1 Define Signal

Signal is a physical quantity that varies with respect to time , space or any other independent variable.
Or It is a mathematical representation of the system Eg y(t) = t. and x(t)= sin t.

2 Define system .

A set of components that are connected together to perform the particular task. (ec6303 signals and systems important questions)

3 What are the major classifications of the signal?

(i) Discrete time signal
(ii) Continuous time signal

4 Define discrete time signals and classify them.

Discrete time signals are defined only at discrete times, and for these signals, the independent variable
takes on only a discrete set of values. (ec6303 signals and systems important questions)

Classification of discrete time signal:
i. Periodic and Aperiodic signal
ii. Even and Odd signal
iii. Causal Non Causal
iv. Energy and Power

5 Define continuous time signals and classify them.

Continuous time signals are defined for a continuous of values of the independent variable. In the case of
continuous time signals the independent variable is continuous. For example:
(i) A speech signal as a function of time
(ii) Atmospheric pressure as a function of altitude  (ec6303 signals and systems important questions)

Classification of continuous time signal:
i. Periodic and Aperiodic signal
ii. Even and Odd signal
iii. Causal Non Causal
iv. Energy and Power
v. Random and Deterministic Signals

6 Define discrete time unit step &unit impulse.

Discrete time Unit impulse is defined as
δ [n]= {0, n ≠ 0
{1, n=0 Unit impulse is also known as unit sample.
Discrete time unit step signal is defined by
U[n]={0,n=0
{1,n>= 0

7 Define continuous time unit step and unit impulse.

Continuous time unit impulse is defined as
δ (t)={1, t=0
{0, t ≠ 0

Continuous time Unit step signal is defined as
U(t)={0, t<0
{1, t ≥ 0 (ec6303 signals and systems important questions)

Subject Name	Signals and Systems
Subject Code	EC6303
Regulation	2013

EC6303 Signals and Systems Important questions click here to download

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EC6302 Digital Electronics Important questions

EC6302 Digital Electronics Important questions Regulation 2013 Anna University free download. Digital Electronics EC6302 Important questions pdf free download.

Sample EC6302 Digital Electronics Important questions:

1. Define Digital Systems.

A system which processing discrete or digital signal is called as Digital
System.

2. What is meant by bit?

A binary digit is called bit.

3. What is the best example of digital system? (ec6302 digital electronics important questions)

Digital computer is the best example of a digital system.

4. Define Radix.

It specifies the number of symbols used for corresponding number system.

5. Define Nibble and Byte.

i). In binary number a group of four bits.
ii). A group of 8 bits are called Byte.

6. List the number systems?

i) Decimal Number system
ii) Binary Number system
iii) Octal Number system
iv) Hexadecimal Number system (ec6302 digital electronics important questions)

7. Define binary logic?

Binary logic consists of binary variables and logical operations. The variables
are designated by the alphabets such as A, B, C, x, y, z, etc., with each variable having only two distinct values: 1 and 0. There are three basic logic operations: AND, OR, and NOT.

8. What is a Logic gate?

Logic gates are the basic elements that make up a digital system. The
electronic gate is a circuit that is able to operate on a number of binary inputs in
order to perform a particular logical function. (ec6302 digital electronics important questions)

9. What are the basic digital logic gates?

The three basic logic gates are:
1. AND gate
2. OR gate
3. NOT gate

10. Which gates are called as the universal gates? What are its
advantages?

The NAND and NOR gates are called as the universal gates. These gates are
used to perform any type of logic application.

11. How to represent a positive and negative sign in computers?

Positive (+) sign by 0
Negative (-) sign by 1. (ec6302 digital electronics important questions)

Subject Name	Digital Electronics
Subject Code	EC6302
Regulation	2013

EC6302 Digital Electronics Important questions click here to download

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EC6301 Object Oriented Programming and Data Structures important questions

EC6301 Object Oriented Programming and Data Structures important questions Regulation 2013 Anna University free download. Object Oriented Programming and Data Structures EC6301 important questions pdf free download.

Sample EC6301 Object Oriented Programming and Data Structures important questions:

1. Difference between Class and structure? [April -2010, Dec-2012]

Class is the ADT where as structure is udt. Class needs access specifier such as private, public & private where as structure members can be accessed by public by default & don’t need any accessfiers. Class is oops where structure is borrowed from traditional structured [pop] concept.

2. What is abstract Class? [Nov-2009]

An abstract class is a class that is designed to be specifically used as a base class. An abstract class contains at least one pure virtual function. You declare a pure virtual function by using a pure specifier [= 0] in the declaration of a virtual member function in the class declaration. (EC6301 Object Oriented Programming and Data Structures important questions)

3. List out the advantages of new operator over malloc[] [Dec-2012]

It automatically computes the size of the data object.
It automatically returns the correct pointer type
It is possible to initialize the objects while creating_ the memory space.
It can be overloaded.

4. What are the basic concepts of OOS? [ April -2011]
Objects.
Classes.
Data abstraction and Encapsulation.
Inheritance.
Polymorphism.
Dynamic binding.
Message passing (EC6301 Object Oriented Programming and Data Structures important questions)

5. What is the difference between local variable and data member? [Nov-2011]

A data member belongs to an object of a class whereas local variable belongs to its current scope. A local variable is declared within the body of a function and can be used only from the point at which it is declared to the immediately following closing brace. A data member is declared in a class definition, but not in the body of any of the class member functions. Data members are accessible to all member function of the class. (EC6301 Object Oriented Programming and Data Structures important questions)

Subject Name	Object Oriented Programming and Data Structures
Subject Code	EC6301
Regulation	2013

EC6301 Object Oriented Programming and Data Structures Important questions click here to download

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EE6352 Electrical Engineering and Instrumentation Important questions

EE6352 Electrical Engineering and Instrumentation Important questions Regulation 2013 Anna University free download. Electrical Engineering and Instrumentation EE6352 Important questions pdf free download.

Sample EE6352 Electrical Engineering and Instrumentation Important questions

1. How will you find the direction of emf using Fleming’s Right Hand Rule?

The thumb, the forefinger and the middle finger of the right hand are held so that these fingers are mutually perpendicular, then Forefinger – Field Thumb – Motion Middle finger- I, current

2. How will you find the direction of force produced using Fleming’s Left Hand
Rule?

The thumb , forefinger and middle finger of the left hand are held so that those fingers are mutually perpendicular then Forefinger – Field Thumb – Motion(due to force) Middle finger – I, current (ee6352 electrical engineering and instrumentation Important questions)

3. How are armature windings classified based on the placement of the coil inside the armature slots?

Single layer winding and Double layer winding

4. Write down the emf equation for d.c generator.

E = (фNZ / 60)(P/A) V Where P= number of poles Z= Total number of conductors
A= number of parallel paths Ф= flux per pole N= speed in rpm

5. Why the armature core in d.c machines is constructed with laminated steel sheets instead of solid steel steel?

Steel sheets offer low relutance path for the magnetic field , laminated sheets reduce eddy current loss. (ee6352 electrical engineering and instrumentation Important questions)

6. Why is commutator employed in d.c machines?

• Conduct electricity between armature and fixed brushes
• Converts altenatingemf into unidirectional emf and vice versa

7. Distinguish between shunt and series field coil constructions.

Shunt field coils are wound with wires of small cross section and have more number of turns. Series field coils are wound with wires of larger cross section and have less number of turns. (ee6352 electrical engineering and instrumentation Important questions)

Subject Name	Electrical Engineering and Instrumentation
Subject Code	EE6352
Regulation	2013

EE6352 Electrical Engineering and Instrumentation Important questions click here to download

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