BLBCTIlUCAL BNGINBBIlUNG

Time Allowed: 3 Hours Maximum marks: 3m
Candidates should attempt Questions 1 and 5 which are compulsory, and any three of the rlnlaining questions sdecting at least one question from each Section.


SECTION A
Answer any THREE ofthe following x 20 60)
Hicks c1inical thermometer measures human body temperature The instruction is to wait for half-a-mmule before laking the reading. Is it because the measuring system is a
zero order system with a pure time delay 0f ha11-a-minute .
first order system with a time constant greater than half-a-minute?
first order system with a time constant equal 10 half-a-minute?
first order system with a time constant less than half-a-minute Justify your answer

Enumerate the different kinds of head type flow meters used in the industry. What kinds of restrictions. are placed in the flow path for flow measurement? Develop the relationship between flow and pressure differential from phYSical principles Why is it that a rotameter is conSidered a standard in flow measurement?
Give a brief account af application of computers in the study, analySiS and control af power systems

(d)Colour sub-carrier (358 MHz tar FCC standard and 4.43 MHz for CUR standard) iS chosen as some odd multiple af one-half of line frequency. Justify the statement

What iS the difference between a microcomputer and a micro-process? What type of data iS stored in the memory of microcomputer? How much memorties can a typical 8-bit micro­process access? What are the condition flags and why are they important Write the advantage of the indexed address mode compared to the direct addressing mode Draw the time diagram of out instruction for 8085 micro-process


A constant load of 330 MW iS supplied by two 250 MW generators, 1 and for which the respective incremental fuel costs are
df1/dp1=0.12p1+22, and df2/dp2=0.10p2+16
with powers P n MW and costs F in Rs/hr Determine
most economic operating schedule of the generators, and
the saving in Rs./hr there by obtained comp red to equal 10 ad sharing between them
(c)Explain the sea waves phenomena and vortex motion of waves Discuss the principles of two possible devices used for generating electrical energy from the WeNe energy. Draw the block diagram from wave energy device to utility gnd. Write the relation for the potential power In tenns of height of wave and Its time period. If the time peroid of a wave iS 10 secs having height 7 meters, estimate the power that can be generated

How iS the surface layer of silicon dioXide fonned? How thick iS this layer? What are the reasons for fonrung the Silicon dioXide 1ayer?


A25MVA, 11 kV generator has Z1=Z2= jO.2pu and Z0= jO.05pu For a line-to ground fault on the generator tenrminals, find
the fault current and
(ii)the line-to -line voltages dunng the fault condition. Assume that the generator neutral iS solidly grounded and that the generator lS operating at no load and at rated voltage at the time of occurrence of fault Compare this fault current with the line current for a three-phase fault at the tenrunals
A power transfonner is connected In A/fl fashion. Draw the arrangement of the current transfonners on either Side ofthe transfonner for Merz-Pnce circulating current protechon
A distribution transfonner iS to be protected by over-current relays against all kinds of fault. List the different kinds of fault and suggest the minimum number of over­current relays reqUired. How would those over-current relays be placed in the circuit?
How would one protect a direct-on-line start induction motor against overload? Explain your choice
Discuss the phySics of plezo-electric phenomena. Draw the eqUivalent circuit of a piezo­electric transducer and derive the output voltage, Vout of transducer with applied force F Point out the four materials which exhibit the plezo-electric phenomena Also write its applications. A plezo-electric pressure transducer having a charge sensitivity of 2 x 10-12 C/N iS connected to a charge amplifier, the gain being set to 5mV/pC. The amplifier Output iS connected to an ultraviolet chart recorder whose sensitivity lS set to 25 rum/volt. Determme the overall senSivity
(b)With the aid of a block schematic, describe the functiomng of the receving unit of a DBS TV/FM receving system intended for home reception
ConSider an optical fiber with refractive index of the core 1.8 and of cladding 1.7; calculate
Critical angle
(ii)Acceptance angle
(iii)Brewster angle
Numerical aperture


SECTION B
Answer any THREE of the followINg (3x20=60)
What do you understand by dielectric films? State any two dielectric film material and point out thea important properties and applications Explain
the orientation polarization,

(ii)electronic polarization; and
ionic polanzation referred to polyatomic gas Discuss the effect of frequency on electronic polarization and ionic polanriation what is electronegative gases? State the important features of SF6 and its applications
Find the gain and approximate input impedance of the accompanying circuit What iS this circuit called and for what purpose it is used as instrumentation. <img src='./qimages/1146-5b1.jpg'> Analyze the following three Op-Amp based instrumentations amplifier and find itS gam What is its approximate input impedance Assume that the Op-Amps are ideal <img src='./qimages/1146-5b2.jpg'>
Explain why it iS more difficult to interrupt short-circuit current in an HYDC circuit than that man HVAC a circuit In a certain communication system, the message iS coded into binary digits 0 and 1 After coding, the probability of a 0 being sent is 0.45, while the probability of a i being sent is 0.55. In the communication channel, the probability ofa transmitted 0 being converted into a at the receiver is 0 while the probability of a I being distorted into a 0 iS 0.2 Find
the probability that areceived 0 was transmitted as a and
the probability that a received i was transmitted as a 1.
6 (a).Given that the above iS a linear time-invariant system, how would you check the stability of the system? If there iS an unstable mode in the system, iS it controllable? If the unstable mode is controll able shift it to a stable position, say lamda=-0.5,by state feedback
What are the deSign conSiderations for layenng in data networks? Discuss a seven-layer network architecture with a diagram

(c)Why and to what degree do optical Signals get degraded as they propagate along a fiber? Discuss in detail

Which I/O technique provides the highest data transfer rate Explain the function 0f DMA Draw the block diagram of a DMA controller with memory lnterfacing. What is meant by Simultaneous DMA List three different DMA modes for transfemng data. How iS the DMA controller iS programmed? Are speacil buffers required when inerfaces a DMA controller?(20)
A radar receiver has a low noise RF amplifier of noise figure 6 dB and gain 20 dB followed by a mixer of noise figure 6 dB and converSiOn loss of 6 dB. If the noise figure of IF pre­amplifier iS 3 dB with a gain of 26 dB and that of IF main amplifier lS 10 dB, obtain the noise figure of the receiver and its noise temperature

Draw the waveform at the end of one of the vertical fields, showing a horizontal and a vertical blanking pulse. Indicate the duration and relative amplitudes of two pulses and explain their functions. Where are synchronizing pulses placed? Does It matter that there are no horizontal blanking purses during vertical blanking period
A Wheatstone bridge has resistances R1, R2, R3, and R4 in its four arms The bridge iS excited by E volts dc. Assuming that the ratio of arms R1, and R2, are equal, the bridge iS Initially balanced with R3 equal to R4 A slight unbalance (R3 ±deltaR3) iS created by R3 Show that the unbalance voltage, Vo, iS directly proportional to (deltaR3/,IR3) as long (.deltaR3/R3) « 1 WhatiS the condition for maximizing the sensitivity
The figure below shows a generator-transfonner unit feeding! 1.0 pu power to the infinite bus
through a double-circuit transformission line With the generator terminal voltage of V1= 1.0 pu Compute the generator e.mf behind tranSient reactance Also find the maximum power that can be transferred when
the system iS operating under healthy condition,
one line iS shorted (three-phase) in the nuddle, and
one line iS open

<img src='./qimages/1146-8b3.jpg'>
What do you understand by energy conservation? What iS the economics of energy conservation? Pomt out the strategic measures for energy conservation Show that for a given load current!, if power factor iS Improved from 0.7to 0.9, the useful power can be enhanced by 28.6% of the exiSting system. Comment on the losses due to power factor Improvement