Monday, September 28, 2009

links for electrical engg books

Electric_Power_Generation,_Transmission,_and_Distr ibution.rar

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http://www.uploading.com/files/QI8EQS6G/Electric_Power_Generation,_Transmission,_and_Distribution.rar.html

Electric_Power_Distribution_Equipment_and_Systems. rar

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http://www.uploading.com/files/PB4ERLBK/Electric_Power_Distribution_Equipment_and_Systems.rar.html

Electric_Machinery.rar

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http://www.uploading.com/files/D0UX0WE3/Electric_Machinery.rar.html

Electric_Power_Systems.rar

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http://www.uploading.com/files/V9BA9U7R/Electric_Power_Systems.rar.html

Electric_Machinery_Fundamentals.rar

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http://www.uploading.com/files/WBYKXK8J/Electric_Machinery_Fundamentals.rar.html

Electric_Power_Transformer_Engineering.rar

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http://www.uploading.com/files/VZQM32RD/Electric_Power_Transformer_Engineering.rar.html

Electrical_Energy_Systems.rar

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http://www.uploading.com/files/TS01JYO9/Electrical_Energy_Systems.rar.html

Dielectrics_in_Electric_Fields.rar

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http://www.uploading.com/files/QR676NIY/Dielectrics_in_Electric_Fields.rar.html

Electrical_Engineer_Portable_Handbook.rar

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http://www.uploading.com/files/P1R19MJ5/Electrical_Engineer_Portable_Handbook.rar.html

Electrical_Power_Systems_Quality.rar

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http://www.uploading.com/files/S6RQ6QIG/Electrical_Power_Systems_Quality.rar.html

Electric_Power_Substations_Engineering.rar

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http://www.uploading.com/files/RM418VOH/Electric_Power_Substations_Engineering.rar.html

Electrical_Power_Cable_Engineering.rar

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http://www.uploading.com/files/LZ22ZZEA/Electrical_Power_Cable_Engineering.rar.html

Electrical_Measurement,_Signal_Processing,_and_Dis plays.rar

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http://www.uploading.com/files/CJRUQ6SY/Electrical_Measurement,_Signal_Processing,_and_Displays.rar.html

Flexible_AC_Transmission_Systems_Modelling_and_Con trol.rar

Code:

http://www.uploading.com/files/WJOVL2CW/Flexible_AC_Transmission_Systems_Modelling_and_Control.rar.html

Energy-Efficient_Electric_Motors,_Third_Edition_(Electric al_Engi.rar

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http://www.uploading.com/files/K1XC6CYF/Energy-Efficient_Electric_Motors,_Third_Edition_(Electrical_Engi.rar.html

Handbook_of_Modern_Sensors_Physics,_Designs,_and_A pplications.rar

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http://www.uploading.com/files/AS2RZFRV/Handbook_of_Modern_Sensors_Physics,_Designs,_and_Applications.rar.html

Newnes_Electrical_Power_Engineers_Handbook.rar

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http://www.uploading.com/files/BYEJ12ZV/Newnes_Electrical_Power_Engineers_Handbook.rar.html

Power_Electronics_Design__A_Practitioners_Guide.ra r

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http://www.uploading.com/files/R4Z117ZW/Power_Electronics_Design__A_Practitioners_Guide.rar.html

Handbook_of_Transformer_Design_and_Applications.ra r

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http://www.uploading.com/files/WZY8HWC4/Handbook_of_Transformer_Design_and_Applications.rar.html

Power_System_(The_Electric_Power_Engineering).rar

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http://www.uploading.com/files/DZ3IFIGC/Power_System_(The_Electric_Power_Engineering).rar.html

Power_Transformers.rar

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http://www.uploading.com/files/BAKJ4CGC/Power_Transformers.rar.html

Practical_Variable_Speed_Drives_and_Power_Electron ics.rar

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http://www.uploading.com/files/OUKOL9R4/Practical_Variable_Speed_Drives_and_Power_Electronics.rar.html

Power_electronics.rar

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http://www.uploading.com/files/OWII2APQ/Power_electronics.rar.html

Power_System_Stability_and_Control.rar

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http://www.uploading.com/files/7LZ7EPPL/Power_System_Stability_and_Control.rar.html

Radio_and_Electronics_Co.okbook.rar

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http://www.uploading.com/files/2CEGDAWT/Radio_and_Electronics_Co.okbook.rar.html

Synchronous_Generators.rar

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http://www.uploading.com/files/PP2E1VN5/Synchronous_Generators.rar.html

First_Course_on_Power_Electronics_and_Drives.rar

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http://www.uploading.com/files/7A1485QJ/First_Course_on_Power_Electronics_and_Drives.rar.html

The_Electric_Power_Engineering_Handbook.rar

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http://www.uploading.com/files/0VUUN9KI/The_Electric_Power_Engineering_Handbook.rar.html

Transient_Analysis_of_Electric_Power_Circuits_Hand book.rar

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http://www.uploading.com/files/2YHH7T25/Transient_Analysis_of_Electric_Power_Circuits_Handbook.rar.html

Understanding_Electric_Power_Systems.rar

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http://www.uploading.com/files/9MRRWP2V/Understanding_Electric_Power_Systems.rar.html

The_Induction_Machine_Handbook.rar

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http://www.uploading.com/files/B5TEBQXE/The_Induction_Machine_Handbook.rar.html

Understanding_Electric_Utilities_and_De-Regulation.rar

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http://www.uploading.com/files/7NOODYRU/Understanding_Electric_Utilities_and_De-Regulation.rar.html

Uncertainty_in_the_Electric_Power_Industry.rar

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http://www.uploading.com/files/O0IQWQ2Y/Uncertainty_in_the_Electric_Power_Industry.rar.html

Standard_Handbook_for_Electrical_Engineers.rar

Code:

http://www.uploading.com/files/CML5CJ6G/Standard_Handbook_for_Electrical_Engineers.rar.html

Electrical Transmission and Distribution Reference Book.rar

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http://uploading.com/files/XVS8OR0K/Electrical Transmission and Distribution Reference Book.rar.html

Variable Speed Generators.rar

Code:

http://uploading.com/files/H2EHJ7JH/Variable Speed Generators.rar.html

NORTHERN POWER DISTRIBUTION COMPANY OF A.P. Ltd.

NORTHERN POWER DISTRIBUTION COMPANY OF A.P. Ltd.

SYLLABUS FOR WRITTEN TEST OF APNPDCL

ELECTRICAL ENGINEERING GRADUATES - 2009.

Electric Circuits: Network Graph, KCL, KVL, node and mesh analysis, star/delta transformation; electromagnetic induction; mutual induction; ac fundamentals; harmonics, transient response of dc and ac networks, sinusoidal steady-state analysis, resonance, ideal current and voltage sources, Thevenin’s, Norton’s and superposition and maximum power transfer theorems two-port networks, three phase circuits, power measurement.

Electrical Machines: Single-phase transformers - equivalent circuit, phasor diagram, tests regulation and efficiency, three phase transformer-connections, parallel operation, auto transformer, DC machines – types, windings, generators/ motor characteristics, armature reaction and commutation, starting and speed control of motors, three phase induction motors – Principles, types, performance characteristics, starting and speed control, single-phase induction motors, synchronous machines - performance, regulation and parallel operation of generators, motor starting, characteristics and applications.

Power Systems: Basic power generation concepts, transmission line models and performance; underground cable, string insulators; corona; distribution systems; pre-unit quantities; bus impedance and admittance matrices; load flow; voltage control; power factor correction; economic operation; symmetrical components; fault analysis; principles of over – current, differential and distance protection; protection of alternator, transformer, transmission lines neutral earthing, solid state relays and digital protection; circuit breakers; system stability concepts, swing curves and equal area criterion.

Utilization & Controlling Systems: Principles of feedback; transfer function; block diagrams; steady-state errors; Routh and Niquist techniques; Bode plots; root loci; lag, lead and lead-lag compensation; Heating – resistance, induction, dielectric; Welding – spot, seam and butt; Electric traction – speed-time curves, tractive effort;

Measurements: Bridges and potentio meters, PMMC, moving iron, dynamometer and induction type instruments, measurement of voltage, current, power, energy and power factor, digital voltmeters and multimeters; phase, time and frequency measurement, Q-meters, oscilloscopes.

Analog and Digital Electronics: Characteristics of diodes, BJT, FET; amplifiers – biasing, equivalent circuit and frequency response; oscillators and feedback amplifiers; Combinational and sequential logic circuits; multiplexer; Schmitt trigger; A/D and D/A converters; 8-bit microprocessor basics, architecture, programming and interfacing.

Power Electronics and Drives: Semiconductor power diodes, transistors, thyristors, triacs, GTOs, MOSFETs and IGBTs – Static characteristics and principles of operation, triggering circuits, phase control rectifiers, bridge converters, fully controlled and half controlled principles of choppers and inverters; basics concepts of adjustable speed dc and ac drives.

Model of question paper

The question paper consists of one hundred multiple choice objective type questions, to be answered on the OMR answer sheet using HB pencil in 2 hours. A few questions are given as a model below. (CALCULATORS ARE NOT ALLOWED INTO THE EXAMINATION HALL. CANDIDATES HAVE TO BRING THEIR OWN PENCILS AND ERASERS)

1. The armature of a d.c. machine is made of

a. Silicon steel

b. wrought iron

c. cast steel

d. soft iron

A

B

C

D

2. The main drawback of a d.c. shunt generator is that

a. Shunt circuit has high resistance.

b. Generated voltage is small.

c. terminal voltage drops considerably with load.

d. it is expensive.

A

B

C

D

3. Transformers usually transfer electrical energy from primary to secondary with change in

a. Frequency

b. Voltage

c. Power

d. Time period.

A

B

C

D

CHIEF GENERAL MANAGER(HRD)

APNPDCL :: WARANGAL.

TOP 100 WORDS FOR GRE AND TOEFL

TOP 100 WORDS FOR GRE AND TOEFL
-------------------------------------------------------------------------

abyss = hole so deep as to appear bottomless
acquiesce = agree, accept without protest
affable = polite and friendly, easy to talk to
affliction = distress, suffering
affluent = wealthy, abundant
agitate = move, shake, stir up
ambiguous = having more then one meaning
annex = take possession of
aqueous = of or like water
arduous = demanding great effort, strenuous
aroma = quality or surrounding atmosphere considered typical
atone = make repayment
avarice = greed
bellicose = inclined to fighting
calisthenics = exercises to develop strong bodies
captor = person who takes smb captive
concoct = invent, prepare by mixing together
dangle = hand or swing loosely
deprive = take away from, prevent from using
diligent = hard-working
disrobe = undress
docile = easily trained or controlled
doleful = dismal, mourful
drought = a long period of dry weather
dubious = feeling doubt
dumbfound = astonish
efface = rub or wipe out, obliterate
elucidate = to make understandable
enchant = charm, delight
endeavor = to make an effort, to try very hard
endorse = approve, support a claim or statement
enthral = take the whole attention, enslave
exploit = to use for selfish advantage or profit
extensive = far-reaching
extol = to praise highly
flimsy = lacking solidarity, strength
fraud = a fault, a deception
gaudy = too bright and showy
ghastly = death-like, pale and ill
grumble = to complain
harass = worry, trouble
heretic = very busy; active
impediment = smth that hinders (esp in speech)
indigenous = native
insatiate = never satisfied
intrepid = fearless
irate = angry
jeopardy = danger
leash = control
loafer = an idle, lazy person
lucrative = profitable
lustrous = bright; shining
malign = to slander
meddle = to interfere, to intrude
mend = to repair
mirth = being merry and happy
nausea = feeling of sickness
neglect = pay no attention to
nocturnal = of or in the night
obese = very fat
obsolete = no longer useful, outdated
perch = take up a high position
pervade = spread through every part of
petulant = unreasonably impatient or irritable
pillage = plunder (esp in war)
presumptuous = too bold or self-confident
quashed = annuled
quenching = satisfy, put an end to, put out
refurbished = make clean, as if like new
rejoicing = happiness, joy
reticent = in the habit of saying little
reverberate = be sent back, again and again
rigor = sternness, strictness, severe conditions
rotundity = state of being round
salvage = the saving of property from loss
scattered = not situated together
shatter = to break into many pieces
shunned = avoided, kept away from
sketchy = shortly, roughly, quickly
sporadic = happening from time to time
stifled = suppressed, kept back
strive = to make great efforts, to struggle
subsequent = following
succumb = yield, die
taciturn = unspoken, silent
tantalize = raise hopes that cannot be realized
tentative = uncertain, probable
torpid = dull and slow
treacherous = not to be trusted, perfidious
tremor = thrill
tyro = a beginner
uproar = noise and excitement
vanity = a foolish pride
vehemence = forcefulness; intensity; conviction
vigilance = watchfulness
vindicate = prove the truth
voluptuous = arousing sensual pleasures
wan = looking ill, not bright
wile = a trick
wrinkle = make small lines (eg forehead)

Test Paper

ELECTRICAL, ELECTRONICS AND INSTRUMENTATION

1. In order for a 30 volt, 90 watt lamp to work properly in a 120 volt supply the required series resister in ohm is

(A) 10 (B) 20
(C) 30 (D) 40

2. According to Theremin’s theorem, any linear active network can be replaced by a single voltage source

(A) in series with a single impedance
(B) in parallel with a single impedance
(C) in series with two impedances
(D) in parallel with two impedances

3. The internal resistance of ammeter is

(A) very small (B) very high
(C) infinite (D) zero

4. Hay bridge is used mainly for the measurement of

(A) resistance (B) inductance
(C) conductance (D) capacitance

5. Which of the following is true about series resonance

(A) The reactance becomes zero and impedance becomes equal to resistance
(B) The current in the circuit becomes maximum
(C) The voltage drop across inductance and capacitance cancels each other
(D) All of the above statements are correct

6. A 3-Ф, 4 wire, 400/230 v feeder supplies 3-phase motor and an unbalanced lighting load. In this system

(A) all four wires will carry equal current
(B) neutral wire will carry no current
(C) neutral wire will carry both motor current and lighting load current
(D) neutral wire will carry current only when lighting load is switched on

7. Equalizing connections are required when paralleling two

(A) alternators
(B) compound generators
(C) series generators
(D) both (B) and (C)

8. An ideal transformer is one which

(A) has a common core for its primary and secondary windings
(B) has no losses and magnetic leakage
(C) has core of stainless steel and windings of pure copper metal
(D) has interleaved primary and secondary windings

9. The principle of operation of a 3-phase induction motor is most similar to that of a

(A) synchronous motor
(B) repulsion-start induction motor
(C) transformer with a shorted secondary
(D) capacitor-start, induction-run motor

10. In the forward region of its characteristic, a diode appears as

(A) an OFF switch
(B) a high resistance
(C) a capacitor
(D) an ON switch

11. The common-emitter forward amplification factor βdc is given by

(A) IC/IE (B) IC/Ib
(C) IE/IC (D) IB/IF

12. A common emitter amplifier is characterized by

(A) low voltage gain
(B) moderate power gain
(C) signal phase reversal
(D) very high output impedance

13. After VDS reaches pinch-off value VP in a JFET, drain current IO becomes

(A) zero (B) low
(C) saturated (D) reversed

14. An electronic oscillator

(A) needs an external input
(B) provides its own input
(C) is nothing but an amplifier
(D) is just a dc/ac converter

15. In an SCR, the function of the gate is to

(A) switch it off
(B) control its firing
(C) make it unidirectional
(D) reduce forward breakdown voltage

16. NAND and NOR gates are called ‘universal’ gates primarily because they

(A) are available everywhere
(B) are widely used in IC packages
(C) can be combined to produce AND, OR and NOT gates
(D) are the easiest to manufacture

17. Registers and counters are similar in the sense that they both

(A) count pulses
(B) store binary information
(C) are made from an array of flip-flops and gates integrated on a single chip
(D) are in fact shift register

18. A flip-flop

(A) is a sequential logic device
(B) is a combinational logic device
(C) remembers what was previously stored in it
(D) both (A) and (C)

19. An operational amplifier

(A) can be used to sum two or more signals
(B) can be used to subtract two or more signals
(C) uses to principle of feed back
(D) all of the above

20. TTL logic is preferred to DRL logic because

(A) greater fan-out is possible
(B) greater logic levels are possible
(C) greater fan-in is possible
(D) less power consumption is possible

Control Systems

Control Systems

1. An open loop control system has its

(a) control action independent of the output or desired quantity

(b) controlling action, depending upon human judgment

(c) internal system changes automatically taken care of

(d) both (a) and (b)

(e) all (a),(b) and (c)

2. A servo system must have

(a) feedback system

(b) power amplifier to amplify error

(c) capacity to control position or its derivative

(d) all of these

(e) none of these

3. The major disadvantage of a feedback system may be

(a) Inaccuracy

(b) inefficiency

(c) Unreliability

(d) instability

(e) Insensitivity

4. Properties of a transfer function

(a) It is ratio of two polynomials is S and assumes zero initial conditions

(b) It depends on system elements and not input and output of the system

(c) Coefficients of the powers of S in denominator and numerator are all real constant. The order of denominator is usually greater than or equal to the order of numerator

(d) All of these

(e) It is a function which transfer one physical system into another physical system.

5. The classical analogous of a simple lever is

(a) Capacitor bridge

(b) transformer

(c) mutual inductor

(d) either of these

6. Two blocks G1(s) and G2(s) can be cascaded to get resultant transfer function as

(a) G1(s) + G2(s)

(b) G1(s) / G2(s)

(c) G1(s) G2(s)

(d) 1+G1(s) G2(s)

(e) 1-G1(s)G2(s)

(f) two blocks cannot be cascaded

7. The principles of homogeneity and super position can be applied to

(a) linear time invariant system

(b) non-linear time invariant system

(c) digital control system

(d) both (a) and (b)

8. Pick up the nonlinear system

(a) automatic voltage regulator

(b) d.c. servomotor with high field excitation

(c) temperature control of a furnaces using thermistor

(d) speed control using SCR

(e) all of these

9. Signal flow graph (SFG) is a

(a) polar graph

(b) semi log graph

(c) log log graph

(d) a special type of graph for analyzing modem control system

(e) a topological representation of a set of differential equations

10. Disadvantages of magnetic amplifier

(a) time lag, less flexible, non-sinusoidal waveform

(b) low power consumption and isolation of the active circuit

(c) saturation of the core

(d) all of these

11. Pick up false statement regarding magnetic amplifiers

(a) The gate coil of an ideal magnetic amplifier has either zero or infinite inductance

(b) Resistance of control and gate winding is very small

(c) Magnetic amplifier gas dropping load characteristics

(d) Magnetic amplifiers are not used to control the speed of d.c. shunt motor

(e) Magnetic amplifiers can be used in automatic control of electric drivers of higher rating.

12. High power amplification is achieved by using

(a) push pull amplifier

(b) amplidyne

(c) magnetic amplifier

(d) DC amplifier

(e) D.C. generator

13. Pick up false statement regarding servomotors

(a) The d.c. servomotors are lighter than equivalent a.c. servomotors

(b) The d.c. servomotors develops higher starting and reversing torque than equivalent a.c. servomotor.

(c) A drag cup a.c. servomotor has one windings on stator and other on rotor

(d) Output power of servomotors varies from 1/20 W to 100 W

14. To reduce steady state error

(a) decrease natural frequency

(b) decrease damping

(c) increase damped frequency

(d) increase time constant

(f) increase gain constant of the system

15. A good factor for Mp should be

(a) less than 1

(b) lying between 1.1 and 1.5

(c) more than 2.2

(d) zero

(e) infinity

16. Pick up false statement. Routh-Hurwitz criterion

(a) is used for determining stability of a system

(b) is an algebraic procedure

(c) gives the exact location of roots of the characteristic equation

(d) does not indicate relative degree of stability or instability

17. Which of the following is the time domain method of determining stability of a control system

(a) Bode plot

(b) Nyquist plot

(c) Nicholos chart

(d) Routh-Hurwitz array

(e) Constant M and (fy) locus

(f) Root locus technique

18. The technique which gives transient response quickly as well as stability information is

(a) Nyquist plot

(b) Routh-Hurwitz criteria

(c) Bode plot

(d) Root locus plot

(e) Nichols plot

19. The bandwidth can be increased by use of

(a) phase lag network

(b) phase lead network

(c) both (a) and (b) in cascade

(d) both (a) and (b) in parallel

(e) none of these

20. Nyquist plot is drawn on

(a) semi log graph paper

(b) log log graph paper

(c) polar graph paper

(d) centimeter graph paper

21. If the gain margin is positive and the phase margin is negative the system is

(a) stable

(b) unstable

(c) indeterminist

22. The Bode plot is applicable to

(a) all phase network

(b) minimum phase network

(c) maximum phase network

(d) lag lead network

(e) none of these

23. The valid relation between setting time ts and rise time tr is

(a) tr>ts

(b) ts>tr

(c) ts=tr

(d) none of these

24. As a root moves further away from imaginary axis the stability

(a) increases

(b) decreases

(c) not affected

(d) none of these

25. Flat frequency response means that the magnitude ratio of output to input over the bandwidth is

(a) variable

(b) zero

(c) constant

(d) none of above

26. How many octaves are between 200 Hz and 800 Hz

(a) Two octave

(b) One octave

(c) Four octave

(d) None of above

27. Human system can be considered as

(a) open loop system

(b) close loop system with single feedback

(c) close loop system with multivariable feedback

(d) none of these

28. In a feedback system the transient response

(a) Decays at constant rate

(b) gets magnified

(c) decays slowly

(d) decays more quickly

29. Transfer function of a system is used to calculate

(a) the steady state gain

(b) the main constant

(c) the order of system

(d) the output for any given input

(e) all of the above

30. Transfer function of a system is defined as the ratio of output to input in

(a) Laplace transform

(b) Z-transform

(c) Fourier transform

(d) Simple algebraic form

31. Introduction of feedback decreases the effect of

(a) disturbances

(b) noise signals

(c) error signals

(d) all the above

32. The system response of a system can be best tested with

(a) unit impulse input signal

(b) ramp input signal

(c) sinusoidal input signal

(d) exponentially decaying input signal

33. Which of the following is a closed loop system

(a) electric switch

(b) car starter

(c) de generator

(d) auto-pilot for an aircraft

34. Which of the following is used as an error detector

(a) potentiometer

(b) field controlled ac motor

(c) amplidyne

(d) armature controlled ac motor

35. The break away point of root loci are

(a) open loop poles

(b) closed loop poles

(c) open loop zeros

(d) closed loop zeros

36. Noise in a control system can be kept low by

(a) reducing the bandwidth

(b) attenuating such frequencies at which external signals get coupled into the system

(c) both (a) and (b)

(d) none of these

37. Main cause of absolute instability in the control system is

(a) parameters of controlling system

(b) parameters of controlled system

(c) parameters of feedback system

(d) error detector where the two signals are compared

38. Basically a controller is

(a) a amplifier

(b) a clipper

(c) a comparator

(d) a summer

39. A system with gain margin close to unity or a phase margin close to zero is

(a) highly stable

(b) highly oscillatory

(c) relatively stable

(d) none of these

40. Which of following elements is not used in an automatic control system

(a) sensor

(b) error detector

(c) oscillator

(d) final control element

41. AC systems are usually preferred to the DC systems in control applications because

(a) AC systems are cheaper

(b) AC systems are more stable

(c) AC systems have better performance characteristics and smaller in size

(d) all of these

42. A system has the transfer function (1-s)/(1+s); It is known as

(a) low pass system

(b) high pass system

(c) all pass system

(d) none of the above

43. In control systems, excessive bandwidth should be avoided because

(a) noise is proportional to bandwidth

(b) it leads to low relative stability

(c) it leads to slow speed of response

(d) none of these

44. In most systems, an increase in gain leads to

(a) larger damping ratio

(b) smaller damping ratio

(c) constant damping ratio

(d) none of these

45. A step function is applied to the input of a system and output is of the form y = t, the system is

(a) stable

(b) unstable

(c) not necessarily stable

(d) conditionally stable

46. Which of the following can be magnified by magnetic amplifier

(a) voltage

(b) current

(c) power

(d) none of above

47. The inductance is not used in lag network because of

(a) big size

(b) time delay and hysteresis losses

(c) high reactance

(d) none of these

48. Saturation in a stable control system can cause

(a) conditional stability

(b) over damping

(c) low level oscillations

(d) high level oscillations

49. Excessive noise in control systems can cause

(a) reduction in bandwidth

(b) reduction in gain

(c) saturation in amplifying stages

(d) oscillations

50. The type-0 system has

(a) net pole at the origin

(b) no pole at the origin

(c) simple at one origin

(d) two poles at the origin

Network Filters Transmission Lines

Network Filters Transmission Lines

1. Pick up wrong statement

(a) A group of interconnected individual components known as circuit elements is called a network.

(b) A humped network is an arrangement of physically separate resistors, inductors and capacitors.

(c) Distributed network is one, which the resistive, inductive and capacitive effects are inseparable for network analyses.

(d) A branch is a network having four elements.

2. Kirchoff's laws for networks are:

(a) The algebraic sum of branch currents meeting at any node is zero.

(b) The algebric sum of voltage drops in any set of branches forming a closed circuit or loop must be equal to zero.

(c) Both (a) and (b)

(d) Neither (a) and (b)

3. Mutually coupled circuit is a circuit which is:

(a) Bilateral

(b) Unilateral

(c) None of these

(d) Either (a) or (b)

4. Duality is a

(a) Transformation in which current and voltages are interchanged

(b) Active sources become passive sources

(c) Passive sources become active sources

(d) Both (b) and (c)

5. Combined inductance of two inductors L1 and L2 connected and voltages are interchanged

(a) L1 + L2

(b) (L1 + L2)/ L1

(c) (L1 + L2) / (L1 X L2)

(d) (L1 X L2) / (L1 + L2)

6. Normal analysis techniques are based on

(a) Thevenin's theorem

(b) Tellegan's theorem

(c) Superposition theorem

(d) Kirchoff's Law

7. Two voltage sources can be connected in parallel when they are equal in

(a) Magnitude

(b) Frequency

(c) Phase

(d) All the above

8. The kirchoff's law fail in

(a) Linear circuits

(b) Non-linear circuits

(c) Lumped parameter circuits

(d) Distributed parameter circuits

9. Which of the following is a nonreciprocal network ?

(a) A network consisting of all resistances

(b) A network consisting of all capacitances

(c) A network consisting of all inductances

(d) A transistor model

10. When two systems obey equations of the same form the systems are said to be

(a) Similar system

(b) Identical system

(c) Analogous system

(d) Digital system

11. For a highly selective circuit

(a) It must have large value of Q

(b) It must have high value of capacitance to produce resonance at fixed frequency

(c) Either (a) or (b)

(d) Neither (a) nor (b)

12. A network consisting of four terminals is called a

(a) One port network

(b) Two port network

(c) Four port network

(d) None of the above

13. Driving point of a network is

(a) A port where voltage or current source is connected

(b) A terminal where load is connected

(c) A port where load is connected

(d) None of the above

14. Ceramic filters are similar in construction to

(a) Crystal filters

(b) Crystal ladder filters

(c) Crystal lattice

(d) Mechanical filters

15. When two port networks are connected in parallel the resultant

(a) Z parameters are the some of individual parameters

(b) Y- parameters are the some of individual parameters

(c) Both (a) and (b)

(d) Neither (a) nor (b)

16. Electric wave filters

(a) Allow electric signals with specified frequency range

(b) Suppress signals outside a specified range

(c) Both (a) and (b) occurs simultaneously

(d) Either (a) or (b) occur at a time

17. A cascade connection of low pass filter and high pass filter is called

(a) Band pass filter

(b) Band elimination filter

(c) Neither (a) nor (b)

(d) Both (a) and (b)

18. The response of a network is decided by the location of

(a) Its poles

(b) Its zeros

(c) Either (a) nor (b)

(d) Both (a) and (b)

19. Example of two port network is

(a) Transformer

(b) Transmission line

(c) Bridge circuit and transistor circuit

(d) All of the above

20. The circuit whose properties are same in either direction is called

(a) Universal circuit

(b) Reversible circuit

(c) Unilateral circuit

(d) Bilateral circuit

21. Distortion in transmission line is due to

(a) Delay distortion

(b) Phase distortion

(c) Frequency distortion

(d) All the above

22. The general parameters distributed along a transmission line are

(a) R&L only

(b) L&C only

(c) C&G only

(d) R, L, C&G

23. Phase distortion is prominently caused by

(a) circuit transients

(b) non linear characteristics

(c) linearity

(d) none

24. The voltage or current from the receiving end towards the sending end, decreasing in amplitude with increasing distance from the load is called

(a) incident wave

(b) medium wave

(c) reflected wave

(d) none of above

25. E.M. Waves of UHF is propagated efficiently via

(a) parallel wire transmission lines

(b) open wire transmission lines

(c) wave guides

(d) coaxial cables

26. Norton theorem is valid for network containing only

(a) linear elements

(b) no linear elements

(c) resistance

(d) reactance

27. The maximum power is absorbed by one network from other, joined to it at two terminals when the impedance of one is

(a) complex conjugate of other

(b) square root of other

(c) same as other

(d) none of above

28. The decrease in effective conductor cross section at high frequencies

(a) decrease the conductor resistance

(b) increase the conductor resistance

(c) no change in conductor resistance

(d) none of above

29. Voltage standing wave ratio lies in the range

(a) 0 to 1

(b) 1 to infinity

(c) 0 to infinity

(d) -1 to +1

30. Attenuators have applications

(a) in AC circuits only

(b) in DC circuits only

(c) in AC as well DC circuits

(d) in low frequency circuits only

31. In an network

(a) the number of tree branches is equal to the number of links

(b) the number of tree branches cannot be equal to the number of links

(c) the number of tree branches has no relation with the number of links branches

(d) none of these

32. In open line transmission systems, attenuation is more at

(a) lower frequencies

(b) medium frequencies

(c) higher frequencies

(d) remains constant

33. a power ratio 100 is equivalent to

(a) 10 dB

(b) 20 dB

(c) 50 dB

(d) 100 dB

34. The velocity factor for small widely spaced conductors such as open wire line in air is very nearly

(a) 0.66

(b) 0.98

(c) 0.82

(d) 0.76

35. Transmission of power to a load over a transmission line achieves optimum value when standing wave ratio (SWR) becomes

(a) 2 : 1

(b) 1 : 2

(c) 1 : 1

(d) 1 : 10

36. The VSWR in a short circuited loss less transmission line equals

(a) infinity

(b) unity

(c) zero

(d) none of above

37. The velocity factor of a transmission line

(a) is always greater than unity

(b) depend upon the permittivity of the surrounding medium

(c) is lease for air medium

(d) is governed by skin effect

38. Which of the following is not correct

(a) voltage source is an active element

(b) current source is a passive element

(c) resistance is a passive element

(d) conductance is a passive element

39. A network is said to be nonlinear if it does not satisfy

(a) superposition condition

(b) homogeneity condition

(c) both superposition and homogeneity conditions

(d) associative condition

40. An capacitor with zero initial condition at t = 0+ act as a

(a) short circuit

(b) open circuit

(c) current source

(d) voltage source

41. An inductor stores energy in

(a) electrostatic field

(b) electromagnetic field

(c) magnetic field

(d) core

42. In series LCR circuits, at resonance,

(a) current is maximum, power factor is zero

(b) current is maximum, power factor is unity

(c) current is minimum, power factor is unity

(d) none of above

43. In an RCL series circuit, during resonance, the impedance will be

(a) zero

(b) minimum

(c) maximum

(d) none of above

44. When a source is delivering maximum power to load, the efficiency of the circuit is always

(a) 50%

(b) 75%

(c) 100%

(d) None of above

45. In a linear network, when the ac input is doubled, the ac output becomes

(a) two times

(b) four times

(c) half

(d) one forth

46. A passive network has

(a) current sources but no voltage sources

(b) voltage sources but no current sources

(c) both current and voltage sources

(d) no voltage or current sources

47. Two resistances are connected in parallel and each dissipates 50 waits. The total power supplied by the source is

(a) 25 watts

(b) 50 watts

(c) 100 watts

(d) 200 watts

48. Three bulbs of 60 watts each are connected is parallel across 220v, 50 Hz supply. If one bulb burns out

(a) only remaining two will operate

(b) remaining two will not operate

(c) all of three will operate

(d) there will be heavy current from the supply

49. The amplitude of an audio signal is 10 and that of carrier wave is 50. Percentage modulation is:

(a) 0.2

(b) 20

(c) 5

(d) 60

50. The main advantage of PCM system is:

(a) lower bandwidth

(b) lower power

(c) lower noise

Electrical

1. In a D.C. generator, if the brushes are given a small amount of forward shift, the effect of armature is

a. Totally demagnetizing

b. Totally magnetizing

c. Partly demagnetizing and partly cross magnetizing

d. Totally cross magnetizing

2. The air gap between stator and armature of an electric motor is kept as small as possible

a. To get a stronger magnetic field

b. to improve the air circulation

c. To reach the higher speed of rotation

d. To make the rotation easier.

3. Two series motors are coupled. One motor runs as generator and other as motor. The friction losses of the two machines will be equal when

a. Both operates at same voltage

b. Both have same back emf

c. Both have same speed

d. both have same excitation

4. Plugging of D.C. motor is normally executed by

a. Reversing the field polarity

b. Reversing the armature polarity

c. Reversing both the armature and field polarity

d. Connecting a resistance across the armature.

5. Transformer oil transformer provides

a. Insulation and cooling

b. B. Cooling and lubrication

c. Lubrication and insulation

d. Insulation, cooling and lubrication

6. Leakage fluxes of transformer may be minimized by

a. Reducing the magnetizing current to the minimum

b. Reducing the reluctance of the iron core to the minimum

c. Reducing the number of primary and secondary turn to the minimum

d. Sectionalizing and interleaving the primary and secondary windings

7. Electric power is transformed upon one coil to other coil in a transformer

a. Electrically

b. Electro Magnetically

c. Magnetically

d. Physically

8. The most suitable and economical connection for small high voltage transformer is-

a. Star- Delta connection

b. Delta- Delta connection

c. Delta- Star connection

d. Star- Star connection

9. An alternator is said to be over excited when it is operating at

a. Unity power factor

b. Leading power factor

c. Lagging power factor

d. Either lagging or leading power factor

10. In an A.C. machine, the armature winding is kept stationary while the field winding is kept rotating for the following rason

a. Armature handles very large currents and high voltages

b. Armature friction involving deep slots to accommodate large coils is easy if armature is kept stationary

c. Ease of cooling the stator than rotor

d. None of the above.

11. In a synchronous motor, the torque angle is the

a. Angle between the rotating stator flux and rotor poles

b. Angle between the magnetizing current and back emf

c. Angle between the supply voltage and back emf

d. None of the above

12. A 3-phase synchronous motor is said to be "floating" when it operates

a. On no load and without loss

b. On constantly varying load

c. On pulsating load

d. On high load and variable supply voltage

13. Speed of synchronous motor depends upon

a. Number of poles

b. Supply frequency

c. Both (a) and (b)

d. Neither (a) nor (b)

14. Imbalance in the shaft of an induction motor occurs due to

a. Slip rings

b. Overheating of winding

c. Non uniform of air gap

d. Rigid consturcion

15. Squirrel cage induction motor has

a. Zero starting torque

b. Very small starting torque

c. Medium starting torque

d. Very high starting torque

16. The principle of operation of a 3-phase induction motor is similar to that of a

a. Synchronous motor

b. Repulsion - start induction motor

c. Transformer with a shorted secondary

d. Capacitor - start, induction - run motor

17. The speed/load characteristics of a universal motor are similar to those

a. D.C. shunt motor

b. D.C. series motor

c. A.C. motor

d. None of the above

18. Single phase A.C. motor generally used for vacuum cleaners is

a. Universal motor

b. Repulsion motor

c. Hysteresis motor

d. Reluctance motor

19. Buchholz relay is used for the protection of

a. Switch yard

b. Transformers

c. Alternators

d. Transmission lines

20. The type of braking used in traction system is

a. Mechanical braking

b. Electro - pneumatic braking

c. Vacuum braking system

d. All the above

21. The function of processing zenger diode in a UJT circuit used for triggering of SCRs is to

a. Expedite the generation of triggering pulses

b. Delay the generation of triggering pulses

c. Provide a constant voltage to UJT to prevent erratic firing

d. Provide a variable voltage to UJT as the source voltage changes

22. The frequency of a ripple in the output voltage of a 3 - phase semi converter depends upon

a. Firing angle and load resistance

b. Firing angle and supply frequency

c. Firing angle and load inductance

d. Only on load circuit parameters

23. The SCR is turned off when the anode currents falls below

a. Forward current rating

b. Break - over voltage

c. Holding current

d. Latching

24. V4 characteristics of emitter of a UJT is

a. Similar to CE with linear and saturation region

b. Similar to FET with a linear and pinch of region

c. Similar to tunnel diode in some respects

d. Linear between the peak point and valley point

25. A transformer works on

a. DC

b. AC

c. AC & DC both

d. Neither AC not DC

26. Which of the following device is used in transformer?

a. Tube light

b. Electric heater

c. Mobile phone

d. Rectifier module

27. Earth electrodes can be in the form of

a. rods or piper

b. stripes

c. plates

d. any of above

28. Carbone or metal brushes are used in

a. DC generators only

b. AC generators only

c. Both AC & DC generation

d. None of above

29. Energy is lost due to Joule's heating effects in winding of transformer. This is called

a. Copper loss

b. Eddy current loss

c. Flux loss

d. None

30. In refrigeration cycle heat is lost in

a. Cooling coil

b. Condenser

c. Compressor

d. Expansion valve

31. The power factor of AC circuit is

a. R/X

b. R/Z

c. Z/R

d. Zero

32. Silicon controlled output is good if ripple factor is

a. Switch

b. Transformer

c. Amplifier

d. None of above

33. The rectifier output is good if ripple factor is\

a. More

b. Less

c. Constant

d. None of above

34. Protective relays can monitor large AC current by means of

a. Current transformer

b. Potential transformer

c. Micro transformer

d. None of above

35. The combines AM of two similar batteries connected in parallel is:

a. halved

b. doubled

c. remain constant

d. none of above

36. The current in circuit having 5 V EMI source and 10 Ohm resistance is:

a. 2 Amp

b. 50 Amp

c. 5 Amp

d. ½ Amp

37. The chopper is a device to change

a. Voltage

b. Current

c. Frequency

d. None of these

38. The power consumption, in case of centrifugal loads (like pump, fan, blower etc) is proportional to:

a. speed

b. square of speed

c. cube of speed

d. none of these

39. Which of these need to be measured after rewinding the motor:

a. no load current

b. air gap

c. winding resistance

d. all of the above

40. Five percent increase in supply frequency will change the synchronous speed of motor by:

a. -5%

b. +5%

c. -10%

d. +10%

41. Which of the following is the best inverter?

a. square wave inverter

b. sine wave inverter

c. pure sine wave inverter

d. triangular wave inverter

42. For driving a motor in a tape recorder or record player, the motor used is generally:

a. a synchronous motor

b. a hydraulic motor

c. an induction motor

d. a dc series motor

43. The DC motor starter used with a constant speed shunt motor is:

a. 2 point starter

b. 3 point starter

c. 4 point starter

d. 5 point starter

44. A commutator in a DC motor converts

a. AC to DC

b. DC to AC

c. Both AC to DC and DC to AC

d. None of these

45. Two transformers running in parallel will share the load according to their:

a. leakage reactance

b. pu impedance

c. efficiency

d. rating

46. The size of the Earth Wire is determined by:

a. the ampere capacity of the service wires

b. the atmospheric conditions

c. the voltage of service wires

d. none of these

47. The function of lightning arrester is:

a. to limit the short circuit fault current

b. to provide path to high voltage surge to earth

c. to reduce arcing

d. none of these

48. Surge protector provide:

a. high impedance to normal voltage

b. low impedance to surge

c. both (a) and (b)

d. none of these

49. Earthing is necessary to give protection against

a. voltage fluctuation

b. overloading

c. danger of electric shock

d. high temperature of conductors

50. The primary function of fuse is to

a. protect the appliance

b. open the circuit

c. prevent excessive current

d. protect the line

Induction Machines

Induction Machines



1.Speed of the stator field of an Induction motor is

(a) Synchronous speed
(b) Any speed
(c) Less than Synchronous
(d) Slip Speed
Ans(a) Synchronous speed

2.Difference in speed between stator field and rotor
(a) Full load speed
(b)No load speed
(c)Slip
(d) Regulation
Ans:(c)Slip

3.Frequency of current in rotor

(a)Supply frequency
(b)Less than supply frequency
(c)Greater than supply frequency
(d)Slip frequency

Ans;(d) Slip Frequency

4. Shape of the torque slip curve is
(a) Rectangular Hyperbola
(b)Parabola
(c)Sine
(d) Cosine
Ans;(a) Rectangular Hyperbola

5.Machine with negative slip
(a)Induction Motor
(b) Brake
(c)Induction Generator
(d)Synchronous machine
Ans(c) Induction Generator



6.When rotor is at standstill
(a)slip is zero
(b)slip is one
(c)Any slip
(d)Slip is infinity
Ans;(b)Slip is one

7.When the motor runs at synchronous speed slip is
(a) One
(b) Infinity
(c)Zero
(d)Two
Ans:(c)Zero

8.Which torque is greater
(a)Break down
(b)Full load
(c) No load
(d) Running
Ans:(a) Break down

9.An Induction motor is analogous to
(a)DC motor
(b)Transformer
(c)Synchronous motor
(d) DC Generator
Ans:(b)Transformer

10.Blocked rotor test is analogous to
(a) SC test
(b)OC test
(c)Swinburnes
(d) Load test
Ans:(a)SC test

11.No load test is analogous to
(a) SC test
(b) Load test
(c)OC test
(d)Swinburnes test
Ans:(c)OC test

12.Rotor Copper loss is equal to
(a)Friction loss
(b)Stator loss
(c)slip times rotor input
(d)rotational loss
Ans: (c)slip times rotor input

13.For the purpose of plugging
(a)N is positive w.r.t to Ns
(b)N is zero
(c)N is infinity
(d)N is negative w.r.t to Ns
Ans: (d)N is negative w.r.t to Ns

14.Parameter from no load test is
(a)Ri and Xi
(b)Ro and Xo
(c) Copper loss
(d)Impedance
Ans:(b)Ro and Xo


15.If stator field is rotating in clockwise direction rotor rotates in
(a) Any direction
(b)Cannot predict
(c)Anticlockwise
(d) clockwise
Ans: (d)clockwise

16.Blocked rotor test is conducted at
(a)High voltage
(b)Rated current
(c)High current
(d)Rated voltage
Ans(b)Rated current

17.Speed of rotor field in space
(a)N
(b)Any speed
(c)Ns
(d)Slip speed
Ans(c)Ns

18.Line joining tangent and output line in a circle diagram gives
(a)Cu loss
(b)Stator loss
(c)Maximum output
(d)Maximum Torque
Ans;(c)maximum Output


19..Line joining tangent and Torque line in a circle diagram gives
(a)Cu loss
(b)Stator loss
(c)Maximum output
(d)Maximum Torque
Ans;(d)maximum Torque


20.No load test is conducted at


(a)High voltage
(b)Rated current
(c)High current
(d)Rated voltage
Ans: (d)Rated voltage

Digital electronics

Digital electronics


1.The number of digits in octal system is
a.8
b.7
c.10
d. none

2..The number of digits in Hexadecimal system is
a.15
b.17
c.16
d. 8

3.The number of bits in a nibble is
a.16
b.5
c.4
d.8

4.The digit F in Hexadecimal system is equivalent to ------ in decimal system
a.16
b.15
c.17
d. 8

5.Which of the following binary numbers is equivalent to decimal 10
a.1000
b.1100
c.1010
d.1001

6.The number FF in Hexadecimal system is equivalent to ------ in decimal system
a.256
b.255
c.240
d.239

7.IC s are
a. analog
b. digital
c. both analog and digital
d. mostly analog

8.The rate of change of digital signals between High and Low Level is
a. very fast
b. fast
c. slow
d. very slow

9. Digital circuits mostly use
a. Diodes
b. Bipolar transistors
c. Diode and Bipolar transistors
d. Bipolar transistors and FETs

10.Logic pulser
a. generates short duration pulses
b. generate long duration pulses
c. generates long and short duration
d. none of above

11.What is the output state of an OR gate if the inputs are 0 and 1?
a.0
b.1
c.3
d.2

12.What is the output state of an AND gate if the inputs are 0 and 1?
a.0
b.1
c.3
d.2

13.A NOT gate has...
a. Two inputs and one output
b. One input and one output
c. One input and two outputs
d. none of above

14.An OR gate has...
a. Two inputs and one output
b. One input and one output
c. One input and two outputs
d. none of above

15.The output of a logic gate can be one of two _____?
a. Inputs
b. Gates
c.States
d. none

16.Logic states can only be ___ or 0.
a. 3
b. 2
c.1
d.0

17.The output of a ____ gate is only 1 when all of its inputs are 1
a. NOR
b. XOR
c. AND
d. NOT

18.A NAND gate is equivalent to an AND gate plus a .... gate put together.
a. NOR
b. NOT
c. XOR
d. none

19.Half adder circuit is ______?
a. Half of an AND gate
b. A circuit to add two bits together
c. Half of a NAND gate
d. none of above

20. Numbers are stored and transmitted inside a computer in
a. binary form
b. ASCII code form
c. decimal form
d. alphanumeric form

21.The decimal number 127 may be represented by
a. 1111 1111B
b. 1000 0000B
c. EEH
d. 0111 1111

22.. A byte corresponds to
a. 4 bits
b. 8 bits
c. 16 bits
d. 32 bits

23.A gigabyte represents
a.1 billion bytes
b. 1000 kilobytes
c. 230 bytes
d. 1024 bytes

24. A megabyte represents
a. 1 million bytes
b. 1000 kilobytes
c. 220 bytes
d. 1024 bytes

25.. A Kb corresponds to
a. 1024 bits
b. 1000 bytes
c.210 bytes
d. 210 bits

26.A parity bit is
a. used to indicate uppercase letters
b. used to detect errors
c. is the first bit in a byte
d. is the last bit in a byte

27. Which of these devices are two state.
a. lamp
b. punched card
c. magnetic tape
d. all the above

The output impedance of of a logic pulser is
a. low
b. high
c. may be low or high
d. none of above

28.The number of LED display indicators in logic probe are
a.1
b.2
c.1 or 2
d.4

29.In hexadecimal number system,A is equal to decimal number
a.10
b.11
c.17
d.18

30.Hexadecimal number F is equal to octal number
a.15
b.16
c.17
d.18

31.Hexadecimal number E is equal to binary number
a.1110
b.1101
c.1001
d.1111

32.Binary number 1101 is equal to octal number
a.15
b.16
c.17
d.14

33.Octal number 12 is equal to decimal number
a.8
b.11
c.9
d. none

34.Decimal number 10 is equal to binary number
a.1110
b.1000
c.1001
d.1010

35.Binary number 110011011001 is equal to decimal number
a.3289
b.2289
c.1289
d.289

36.1111+11111=
a.101111
b.101110
c.111111
d.011111

37.Binary multiplication 1*0=
a.1
b.0
c.10
d.11

38.110012 -100012=
a.10000
b.01000
c.00100
d.00001

39.10112*1012=
a.55
b.45
c.35
d.25

40.1110112*100012=
a.111101101
b.111101100
c.111110
d.1100110

41.4 bits is equal to
a. 1 nibble
b.1 byte
c. 2 byte
d. none of above

42. which is non-volatile memory
a. RAM
b. ROM
c. both
d. none

43. The contents of these chips are lost when the computer is switched off?
a. ROM chips
b. RAM chips
c. DRAM chips
d. none of above

44.What are responsible for storing permanent data and instructions.?
a. RAM chips
b. ROM chips
c. DRAM chips
d. none of above

45. Which parts of the computer perform arithmetic calculations?
a. ALU
b. Registers
c. Logic bus
d. none of above

46.How many bits of information can each memory cell in a computer chip hold?
a. 0 bits
b. 1 bit
c. 8 bits
d. 2 bits

47.What type of computer chips are said to be volatile?
a. RAM chips
b. ROM chips
c. DRAM
d. none of above

48.Which generation of computer uses more than one microprocessor?
a. Second generation
b. Fifth generation
c.Third generation
d .none of above

49.Which generation of computer developed using integrated circuits?
a. Second generation
b. Fifth generation
c. Third generation
d. none of above

50.Which generation of computer was developed from microchips?
a. Second generation
b. Third generation
c. Fourth generation
d. none of above

51.RAM can be expanded to a
a. increase word size
b. increase word number
c. increase word size or increase word number
d. none of above

52. Which memory is available in all technologies
a. PROM
b. EEPROM
c. ROM
d. EPROM

53. Which memory does not require programming equipment
a. PROM
b. EEPROM
c. ROM
d. EPROM

54. In CCD
a. small charge is deposited for logical 1
b. small charge is deposited for logical 0 or 1
c. small charge is deposited for logical 0 and large charge for logical 1
d. none of above

55. The internal structure of PLA is similar to
a. RAM
b. ROM
c. both RAM or ROM
d. neither RAM nor RAM

56.An output of combinational ckt depends on
a. present inputs
b. previous inputs
c. both present and previous
d .none of above

57.Which are combinational gates
a. NAND & NOR
b. NOT & AND
c. X-OR & X-NOR
d. none of above

58.. As access time is decreased, the cost of memory
a. remains the same
b. increases
c. decreases
d. may increase or decrease

59. Which is correct:
a. A.A=0
b. A+1=A
c. A+A=A'
d. A'.A'=0

60.A counter is a
a. Sequential ckt
b. Combinational ckt
c. both combinational and sequential ckt
d. none of above

61.The parity bit is
a. always 1
b. always 0
c.1 or 0
d.none of above

62.In 2 out of 5 code,decimal number 8 is
a.11000
b.10100
c.1100
d.1010

63.In number of information bits is 11,the number of parity
Bits in hamming code is
a.5
b.4
c.3
d.2

64.For a 4096*8 EPROM ,the number of address lines is
a.14
b.12
c.10
d.8

65. 23.6 10=……….2
a.11111.10011
b.10111.10011
c.00111.101
d.10111.1

66.BCD number 0110011=…….10
a.66
b.67
c.68
d.69

67.The total number of input states for 4 input or gate is
a.20
b.16
c.12
d.8

68.In a 4 input OR gate,the total number of High outputs for the 16 input states are
a.16
b.15
c.13

d. none of above
69.In a 4 input AND gate,the total number of High outputs for the 16 input states are
a.16
b.8
c.4
d.1

70.a buffer is
a. always non-inverting
b.always inverting
c. inverting or non-inverting
d.none of above

71.An AND gate has two inputs A and B and ine inhibits input S.Output is 1 if
a.A=1,B=1,S=1
b. A=1,B=1,S=0
c. A=1,B=0,S=1
d. A=1,B=0,S=0

72. An AND gate has two inputs A and B and ine inhibits input S.Out of total 8 input states,Output is 1 in
a. 1 states
b. 2 states
c. 3 states
d. 4 states

73.In a 3 input NOR gate,the number of states in which output is 1 equals
a. 1
b. 2
c. 3
d. 4

74.Which of these are universal gates
a. only NOR
b. only NAND
c. both NOR and NAND
d. NOT,AND,OR

75. In a 3 input NAND gate,the number of gates in which output in 1equals
a.8
b.7
c.6
d..5

76. A XOR gate has inputs A and B and output Y.Then the output equation is
a.Y=A+B
b.Y=AB+A’B
c.AB+ AB’
d.AB’+A’B’

77.A 14 pin NOT gate IC has………..NOT gates
a.8
b.6
c.5
d.4

78.A 14 pin AND gate IC has………..AND gates
a.8
b.6
c.4
d.2

79.The first contribution to logic was made by
a. George Boole
b. Copernicus
c. Aristotle
d. Shannon

80.Boolean Alzebra obeys
a. commutative law
b. associative law
c. distributive law
d. commutative, associative, distributive law

81. A+(B.C)=
a. A.B+C
b. A.B+A.C
c. A
d.(A+B).(A+C)

82.A.0=
a. 1
b. A
c. 0
d. A or 1

83.A+A.B=
a. B
b. A.B
c. A
d. A or B

84.Demorgan’s first theorem is
a. A.A’=0
b. A’’=A
c. (A+B)’=A’.B’
d. (AB)’=A’+B’
85. Demorgan’s second theorem is
a. A.A’=0
b. A’’=A
c. (A+B)’=A’.B’
d. (AB)’=A’+B’

86. Which of the following is true
a. SOP is a two level logic
b. POS is a two level logic
c. both SOP and POS are two level logic
d. Hybrid function is two level logic

87.The problem of logic race occurs in
a. SOP functions
b. Hybrod functions
c. POS functions
d. SOP and POS functions

88. In which function is each term known as min term
a. SOP
b. POS
c. Hybrid
d. both SOP and POS

89. In which function is each term known as max term
a. SOP
b. POS
c. Hybrid
d. both SOP and Hybrid

90. In the expression A+BC, the total number of min terms will be
a.2
b. 3
c.4
d. 5

91.The min term designation for ABCD is
a.m0
b. m10
c. m14
d. m15

92. The function Y=AC+BD+EF is
a. POS
b. SOP
c. Hybrid
d. none of above

93. The expression Y=∏M(0,1,3,4) is
a. POS
b. SOP
c. Hybrid
d. none of above

94. AB+AB’=
a. B
b. A
c.1
d. 0

95. In a four variable Karnaugh map eight adjacent cells give a
a. Two variable term
b. single variable term
c. Three variable term
d. four variable term

96.A karnaugh map with 4 variables has
a. 2 cells
b. 4 cells
c. 8 cells
d.16 cells

97.In a karnaugh map for an expression having ‘don’t care terms’ the don’t cares
can be treated as
a. 0
b. 1
c. 1 or 0
d. none of above

98. The term VLSI generally refers to a digital IC having
a. more than 1000 gates
b. more than 100 gates
c. more than 1000 but less than 9999 gates
d. more than 100 but less than 999 gates

99.Typical size of an IC is about
a.1”*1”
b. 2”*2”
c. 0.1”*0.1”
d. 0.0001”*0.0001”

100.A digital clock uses…………..chip
a. SSI
b. LSI
c. VLSI
d. MSI

101. Digital technologies being used now-a-days are
a. DTL and EMOS
b. TTL, ECL, CMOS and RTL
c. TTL, ECL and CMOS
d. TTL, ECL, CMOS and DTL

102. A TTL circuit with totem pole output has
a. high output impedance
b. low output impedance
c. very high output impedance
d. any of above

103. TTL uses
a. multi emitter transistors
b. multi collector transistors
c. multi base transistors
d. multi emitter or collector transistors

104. Advanced schottky is a part of
a. ECL family
b. CMOS family
c. TTL family
d. none of above

105. For wired AND connection we should use
a. TTL gates with active pull up
b. TTL gates with open collector
c. TTL gates without active pull up and with open collector
d. any of above

106. Time delay of a TTL family is about
a. 180ns
b. 50ns
c. 18ns
d. 3 ns

107. As compared to TTL, ECL has
a. lower power dissipation
b. lower propagation delay
c. higher propagation delay
d. higher noise margin

108. As compared to TTL, CMOS logic has
a. higher speed of operation
b. higher power dissipation
c. smaller physical size
d. all of above

109. 74HCT00 series is
a.NAND IC
b. interface between TTL and CMOS
c. inverting IC
d. NOR IC

110.CD 4010 is a
a. inverting buffer
b. non inverting hex buffer
c. NOR IC
d. NAND IC

111. Current requirement of a piezo buffer is about
a. 100mA
b. 20mA
c. 4 mA
d. 0.4 mA

112. TSL inverter has
a. one input
b. two inputs
c. one or two inputs
d. three inputs

113. Parallel adder is
a. sequential circuits
b. combinational circuits
c. either sequential or combinational circuits
d. none of above

114. The inputs to a 3 bit binary adder are 1112 and 1102. The output will be
a.101
b.1101
c.1111
d.1110

115. A half adder can be used only for adding
a. 1s
b. 2s
c. 4s
d. 8s

116. A 3 bit binary adder should be
a. 3 full adders
b. 2 full adders and 1 half adder
c. 1 full adder and 2 half adder
d. 3 half adders

117. when two 4 bit parallel adders are cascaded we get
a. 4 bit parallel adder
b. 8 bit parallel adder
c. 16 bit parallel adder
d. none of above

118. The widely used binary multiplication method is
a. repeated addition
b. add and shift
c. shift and add
d. any of above

119.When microprocessor processes both positive and negative numbers, the representation used is
a. 1’s complement
b. 2’s complement
c. signed binary
d. any of above

120. Decimal -90 =………….in 8 bit 2s complement
a.1000 1000
b.1010 0110
c.1100 1100
d.0101 0101

121. In 2’s complement addition, the carry generated in the last stage is
a. added to LSB
b. neglected
c. added to bit next to MSB
d. added to the bit next to LSB

122. The number of inputs and outputs in a full adder are
a. 2 and 1
b. 2 and 2
c. 3 and 3
d. 3 and 2

123.In a 7 segment display the segments a,c,d,f,g are lit. The decimal number
displayed will be
a. 9
b. 5
c. 4
d. 2

124. In a 7 segment display the segments b and c are lit up. The decimal number
displayed will be
a. 9
b. 7
c. 3
d. 1

125 .A device which converts BCD to seven segments is called
a. encoder
b. decoder
c. multiplexer
d. none of these

126. Which device use the nematic fluid
a. LED
b. LCD
c. VF display
d. none of these

127. Which of these is the most recent device
a. LED
b. LCD
c. VF display
d. a and c

128. VF glows with ………. Colour when activated
a. red
b. orange
c. bluish green
d. none of these

129. Which display device resembles vacuum tube
a. LED
b. LCD
c. VF
d. none of these

130.Which device changes parallel data to serial data
a. decoder
b. multiplexer
c. demultiplexer
d. flip flop

131.A 1 of 4 multiplexer requires…… data select line
a. 1
b. 2
c. 3
d. 4

132. It is desired to route data from many registers to one register. The device needed is
a. decoder
b. multiplexer
c. demultiplexer
d. counter

133.Which device has one input and many outputs
a. flip flop
b. multiplexer
c. demultiplexer
d. counter

134.Two 16:1 and one 2:1 multiplexers can be connected to form a
a. 16:1 multiplexer
b. 32:1 multiplexer
c. 64:1 multiplexer
d. 8:1 multiplexer

135. A flip flop is a
a. combinational circuit
b. memory element
c. arithmetic element
d. memory or arithmetic

136. I n a D latch
a. data bit D is fed to S input and D’ to R input
b. data bit D is fed to R input and D’ to S input
c. data bit D is fed to both R and S inputs
d. data bit D’ is not fed to any input

137. I n a D latch
a. a high D sets the latch and low D resets it
b. a low D sets the latch and high D resets it
c. race can occur
d. none of above

138.In a positive edge triggered JK flip flop
a. High J and High K produce inactive state
b. Low J and High K produce inactive state
c. High J and Low K produce inactive state
d. Low J and Low K produce inactive state

139.In a positive edge triggered D flip flop
a. D input is called direct set
b.Preset is called direct reset
c. present and clear are called direct set and reset respectively
d. D input overrides other inputs

140. In a positive edge triggered JK flip flop
J=1,K=0 and clock pulse is rising.Q will
a. be 0
b. be 1
c. show no change
d. toggle

141. For edge triggering in flip flops manufacturers use
a. RC circuit
b. direct coupled design
c. either RC circuit or direct coupled design
d. none of these

142. In a JK flip flop toggle means
a. set Q=1 and Q’=0
b. set Q=0 and Q’=1
c. change the output to the opposite state
d. no change in input

143. A mod 4 counter will count
a. from 0 to 4
b. from 0 to 3
c. from any number n to n+4
d. none of above

144.A counter has N flip flops. The total number of states are
a. N
b. 2N
c. 2N
d. 4N

145.A counter has modulus of 10. The number of flip flops are
a. 10
b. 5
c. 4
d. 3

146.In a ripple counter
a. whenever a flip flop sets to 1,the next higher FF toggles
b. whenever a flip flop sets to 0,the next higher FF remains unchanged
c. whenever a flip flop sets to 1,the next higher FF faces race condition
d. whenever a flip flop sets to 0,the next higher FF faces race cond

147.A counter has 4 flip flops.It divides the input frequency by
a.4
b. 2
c. 8
d. 16

148. A decade counter skips
a. binary states 1000 to 1111
b. binary states 0000 to 0011
c. binary states 1010 to 1111
d. binary states 1111 and higher

149.The number of flip flops needed for Mod 7 counter are
a. 7
b. 5
c. 3
d. 1

150.A presettable counter with 4 flip flops start counting from
a. 0000
b. 1000
c. any number from 0000 to 1111
d. any number from 0000 to 1000
151.A 4 bit down counter can count from
a. 0000 to 1111
b. 1111 to 0000
c. 000 to 111
d. 111 to 000

152. A 3 bit up-down counter can count from
a. 000 to 111
b. 111 to 000
c. 000 to 111 and also from 111 to 000
d. none of above

153.IC counters are
a. synchronous only
b. asynchronous only
c. both synchronous and asynchronous
d. none of above

154. Shifting digits from left to right and vice versa is needed in
a. storing numbers
b. arithmetic operations
c. counting
d. storing and counting

155. The basic storage element in a digital system is
a. flip flop
b. counter
c. multiplexer
d. encoder

156. The simplest register is
a. buffer register
b. shift register
c. controlled buffer register
d. bidirectional register

157. The basic shift register operations are
a. serial in serial out
b. serial in parallel out
c. parallel in serial out
d. all of above

158. A universal shift register can shift
a. from right to left b. from left to right
c. both from right to left and left to right
d. none of above

159. In a shift register, shifting a bit by one bit means
a. division by 2
b. multiplication by 2
c. subtraction by 2
d. any of above

160. An 8 bit binary number is to be entered into an 8 bit serial shift register. The number of clock pulses required is
a. 1
b. 2
c. 4
d. 8

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