Section-A
1. Identify the correctness of the following
statements. Justify your answers

The root locus gives idea about
system's transient behaviour. 3
For an inherently stable second order
system, all the coefficients of
characteristic equation are of the
same sign. 4
A critically damped system has
sustained oscillations. 3
ln 8085 microprocessor, what is
the advantage of multiplexing the
address bus with a data bus?
Write an assembly level program of
8085 microprocessor to exchange
the contents of DE register pair
with that of HL register pair, using
only PUSH-POP instructions. 5

The transfer function of a thermocouple
relating output voltage to temperature is given by
0-625x10-4 V
s+0.125
Put the transfer function in
standard format and find the values
of characterising parameters of the
thermocouple.

Determine the thermocouple output voltage at t 8 when the thermocouple kept at ambient temperature of 20 at t 0 s is taken to a water bath kept at 80 ?C.
Comment upon 1inearity' and 'sensitivity' of thermistors in comparison to thermocouples. 2
Why is 'lead wire compensation' not required for thermistors? 1
What is the impedance of the ideal load connected to an HVAC transmission line?
What is the nature of the load of an HVAC transmission line by itself, capacitive or inductive?
Which electrical quantity measures the magnitude of electrical load in a system? What is generally the nature of the load current, capacitive or inductive, in the power system? 2
Under which condition is the receiving-end voltage higher than the sending-end voltage in a transmission line? Explain with the help of a phasor diagram. 4
Describe the essential features of protective relay. 10

A binary PCM system uses a uniform quantizer and an 8-bit binary encoder. If the bit rate is 100 what 1s the maximum bandwidth for which the system operates satisfactorily? Determine the output signal to quantization ratio when full-load sinusoidal modulating wave of frequency 1 MHz is applied to the input. 5
A discrete memoryless source is
described by the alphabet
and the corresponding
probability vector
0 17}
Design a Huffman code for this
source; find the average codeword length for the Huffman code; and determine the efficiency of the code. 5
2. For the control system, shown in the
following figure, determine the steadystate
error for a unit step input in terms
of K and K1 where
Determine the value of K1, when steadystate
error is zero 20

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-2a.jpg">


A three-phase, 66 kV/ 11 kV transformer is connected in star/ delta. The transformer is protected by Merz-Price circulating current system. Protecting current transformers on the low-voltage side have a ratio of 250/5. Find the ratio of the current transformer on the high-voltage side. 20
For 8085 microprocessor, explain the CALL instruction, showing the details of main memory and stack. 20
3. Draw power triangles showing the three types of power and their units for-

inductive loads;
capacitive loads. 10

A single-phase, 240 V a.c. voltage is applied to a series circuit whose impedance is 10<60? Q. Find P and and also the power factor of the circuit. 10
The equivalent model of a piezoelectrical
crystal is shown below

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-3b.jpg">

Derive the transfer function relating output voltage (V0 to input displacement (xi Arrange it in standard form and identify the expression for characterising parameters. The charge developed in piezoelectric crystal is related to xi, by a constant kq . 10
"Piezoelectric transducers cannot be used to measure static displacement." Comment upon the statement. State the reason based on the transfer function derived in Part 2
If the lower range of frequency for displacement measurement is 5 kHz with inaccuracy, what is the lower range of frequency for inaccuracy? 8
Explain ASK, FSK and PSK modulation schemes used for transmitting the data. Draw clearly the block diagram for coherent detection and non-coherent detection of FSK modulation scheme. 1 0
A systematic linear block
code encodes the information
sequence X (x1 x2, x3) into code word C (c1 c2 c3, c4 c5 c6) such that c4 is a parity check on c1 and
c2 to make the overall parity even, i.e., c1 EB c2 EB c4 0. Similarly c5 is a parity check on c2 and c3, and c6 is a parity check on c1 and c3.
Determine the generator matrix of this code.
Find the parity check matrix for this code.
Using the parity check matrix, determine the minimum
distance of this code.
How many errors of this code are capable of correcting? 10
4. Under which different conditions a
generator or a number of generators together may lose synchronism or fall out of step in an interconnected
power system? Explain in brief. 10
Relating the torque angle and the rotor angular displacement electrical) of a synchronous generator, derive the 'swing equation' taking into consideration the inertia constant of the machine. Make suitable assumptions. 10
For an 8085 microprocessor, write an assembly level program to transfer the contents of the stack pointer register to the output ports A0 and A1 . Write comments with selected instructions. 20
Some control systems have more than one inputs applied at different points in the system. How do we find the response of such systems, using block diagram algebra? Illustrate your answer with the help of a simple example. 10

For the block diagram representation of the figure shown below, determine the system characteristic equation.
Is the system represented by this block diagram stable? 10

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-4c2.jpg">

Section-B
5. What are the limitations of Routh, Hurwitz and continued fraction stability criteria when used for
determining system stability? What is Nyquist analysis? Where is this technique used? 6
Why are integral and derivative controllers not used in practice? 4
Can the 8085 microprocessor be interrupted before completion of existing Interrupt Service Subroutine
Justify your answer. 10
Draw the basic circuit of an analog series ohmmeter to measure an unknown resistance Rx .
if the standard resistance and meter resistance add up to 20 kQ, and the battery is of 2?0
determine the instnunent indication, when Rx Q. 2

What would be the resistance value marked for 0?5 FSD (full-scale deflection)? 2
What component should be connected and in which way to take care of falling battery voltage? 1
When each time ohmmeter is used, what adjustment is recommended for accurate measurement?
Define an electrical power grid in one sentence. How is it achieved? 2
Write four main advantages of the electrical power grid system. 2
What is the purpose of installing a 'reactor' at a suitable location on a long high-voltage a.c. transmission
line? 2
Write the full form of FACTS. 2
What are the advantages of 'reactive power control' installed on the transmission lines? 2
What is circuit breaker rating? Explain the rated making capacity of a circuit breaker. 5+5-10

A convolutional encoder is given in
the figure below

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-5f.jpg">

Find the impulse response of the encoder.
Find the output code word if the input sequence is all (1111 1 1 5

Determine the channel capacity of band-limited waveform AWGN channel with an input power constraint.
6. What are the basic elements of a static relay? Describe the function of each element. 12
What are the advantages of static overcurrent relays over the electromagnetic form? 8
Draw a block schematic of an 8255- programmable parallel 1/0 device, showing all elements and control word
format. For mode O (simple input and output), determine the addresses of its ports and of the control register. Write a control word in the control register, when port output, port Cu output, port B input and port
CL input. 20

For the block diagram shown in the figure below, find the overall transfer function of the system. Verify the same,using signal-flow graph analysis: 20

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-6c.jpg">

7. Draw the circuit diagram for a single line to ground fault on an unloaded Y-connected generator with its
neutral grounded through reactance. Also draw the connection for three symmetrical component sequence
networks for this case showing the currents and voltages. 10
A synchronous generator rated at 100 MVA, 20 kV has X" X2 20% and X0 5%. Its neutral is grounded through a reactor of 0?32Q. The generator is operating
at rated voltage without load and is disconnected from the system when a single phase to ground fault occurs at its terminals. Find the sub-transient current in the
faulted phase. 1 0
Draw the neat sketch of OSI model. What is the significance of data link layer? Explain the flow-control and error-control mechanism. 1 0

Compute the CRC-4 character for the following message, using a modified divisor constant of 10011 1100 0110 1011 01
The a.c. bridge circuit shown below is used to measure the excitation frequency of the source and the resistance Rx connected in arm CD of the bridge. Arm AB is parallel combination of R1 and Ci arm BC is fixed resistor R2 arm AD is serial combination of R4 and C4

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-7c.jpg">

Find the expression for the unknown resistance Rx at balance. 5
Find the expression for unknown excitation frequency at balance. 5
If R1 200 C1 1 R2 400 c1/c4 0.5 and r4/r1 find the value of Rx in kQ and frequency of excitation in kHz.

8. What is the importance of testing of a circuit breaker? Explain different tests carried out to prove the ability of a circuit breaker. 12=20
Bring out the salient points of relation between OM and DPCM. Draw the block diagram of delta modulator and demodulator. 8
Find the capacity of an additive white Gaussian noise channel with a bandwidth 1 MHz, power 10 W and noise power spectral density
No/2 10-9 W/Hz
Explain cyclic codes.

The circuit given below is made by three ideal operational amplifiers

<img src=".E:anuradhaCIVILS 2012CIVILS MAIN 2012images/189-8c.jpg">

Identify the name of the circuit. Comment upon its CMRR in comparison to op-amp.


Find the expressions for voltages at
points and . 10
if V1 5 V and V2 5?05 V and Ve (voltage at point is 5 find the ratio of R/Rg and R2/R1 when overall gain is divided in the ratio of 10 1 between first and second stage of the circuit.