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BSNL TTA Question Paper: Control Systems Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section E - Control Systems
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
Section E - 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
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section D - Instruments and Measurement
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
SECTION D - Instruments and Measurement
(1) Instrument is a device for determining
(a) the magnitude of a quantity
(b) the physics of a variable
(c) either of the above
(d) both (a) and (b)
(2) Electronic instruments are preferred because they have
(a) no indicating part
(b) low resistance in parallel circuit
(c) very fast response
(d) high resistance in series circuit
(e) no passive elements.
(3) A DC wattmeter essentially consist of
(a) two ammeters
(b) two voltmeters
(c) a voltmeter and an ammeter
(d) a current and potential transformer
(4) Decibel is a unit of
(a) power
(b) impedance
(c) frequency
(d) power ratio
(5) A dc voltmeter may be used directly to measure
(a) frequency
(b) polarity
(c) power factor
(d)power
(6) An accurate voltmeter must have an internal impedance of
(a) very low value
(b) low value
(c) medium value
(d) very high value
(7) The insulation resistance of a transformer winding can be easily measured with
(a) Wheatstone bridge
(b) megger
(c) Kelvin bridge
(d) voltmeter
(8) A 100 V voltmeter has full-scale accuracy of 5%. At its reading of 50 V it will give an error of
(a) 10%
(b) 5%
(c) 2.5%
(d) 1.25%
(9) You are required to check the p. f. of an electric load. No p.f. meter is available. You would use:
(a) a wattmeter
(b) a ammeter, a voltmeter and a wattmeter
(c) a voltmeter and a ammeter
(d) a kWh meter
(10) The resistance of a field coil may be correctly measured by using
(a) a voltmeter and an ammeter
(b) Schering bridge
(c) a Kelvin double bridge
(d) a Maxwell bridge
(11) An analog instrument has output
(a) Pulsating in nature
(b) Sinusoidal in nature
(c) Which is continuous function of time and bears a constant relation to its input
(d) Independent of the input quantity
(12) Basic charge measuring instrument is
(a) Duddel’s oscillograph
(b) Cathode ray oscillograph
(c) Vibration Galvanometer
(d) Bailastic Galvanometer
(e) Battery Charging equipment
(13) A.C. voltage can be measured (using a d.c. instrument) as a value obtained
(a) by subtracting the d.c. reading from it’s a.c. reading.
(b) Using the output function of the multimeter
(c) By using a suitable inductor in series with it
(d) By using a parallel capacitor with it
(e) None of the above
(14) A moving coil permanent magnet ammeter can be used to measure
(a) D. C. current only
(b) A. C. current only
(c) A. C. and D. C. currents
(d) voltage by incorporating a shunt resistance
(e) none of these
(15) Select the wrong statement
(a) the internal resistance of the voltmeter must be high
(b) the internal resistance of ammeter must be low
(c) the poor overload capacity is the main disadvantage of hot wires instrument
(d) the check continuity with multimeter, the highest range should be used.
(e) In moving iron voltmeter, frequency compensation is achieved by connecting a capacitor across its fixed coil.
(16) Which of the following instrument is suitable for measuring both a.c. and d.c.
quantities.
(a) permanent magnet moving coil ammeter.
(b) Induction type ammeter.
(c) Quadrant electrometer.
(d) Moving iron repulsion type ammeter.
(e) Moving iron attraction type voltmeter.
(17) Swamping resistance is used in moving coil instruments to reduce error due to
(a) thermal EMF
(b) temperature
(c) power taken by the instrument
(d) galvanometer sensitivity.
(18) A power factor meter is based on the principle of
(a) electrostatic instrument
(b) Electrodynamometer instrument
(c) Electro thermo type instrument
(d) Rectifier type instrument.
(19) A potentiometer recorder is used for
(a) AC singles
(b) DC signals
(c) both (a) and (b)
(d) time varying signals
(e) none of these.
(20) Transformers used in conjunction with measuring instruments for measuring purposes are called
(a) Measuring transformers
(b) transformer meters
(c) power transformers
(d) instrument transformers
(e) pulse transformers.
(21) Leakage flux in an electrical machine is measure by
(a) Ballistic galvanometer
(b) Flux meter
(c) Either (a) or (b)
(d) Vibration galvanometer
(e) CRO
(22) A C.R.O. is used to indicate
(a) supply waveform
(b) magnitude of the applied voltage
(c) B.H. loop
(d) all of these
(e) Magnitude of the current flowing in it.
(23) An oscillator is a
(a) an amplifier having feedback network
(b) a high gain amplifier
(c) a wide band amplifier
(d) a untuned amplifier
(e) None of these
(24) Distortion can be measured by
(a) Wave meter
(b) Digital filters
(c) Wein bridge circuit
(d) Bridge T filter circuit
(25) Series connected Q- meter is preferable for measurement of components having
(a) high impedance
(b) low impedance
(c) both (a) and (b)
(d) high frequency
(e) low capacitance
(26) A potentiometer is
(a) an active transducer
(b) a passive transducer
(c) a secondary transducer
(d) a digital transducer
(e) a current sensing transducer
(27) The basic components of a digital voltmeter are:
(a) A/D converter and a counter
(b) A/D converted and a rectifier
(c) D/A converter and a counter
(d) Ramp generator and counter
(e) Comparator
(28) Which of the following electrical equipment cannot convert ac into dc
(a) diode
(b) converter
(c) transformer
(d) mercury arc rectifier
(29) Voltage measurement are often taken by using either a voltmeter or
(a) an ammeter
(b) an ohmmeter
(c) an oscillator
(d) a watt-meter
(30)The electric device which blocks DC but allows AC is called:
(a) capacitance
(b) inductor
(c) an oscilloscope
(d) a watt-meter
(31 ) The range of an ammeter can be extended by using a
(a) shunt in series
(b) shunt in parallel
(c) multiplier in series
(d) multiplier in parallel
(32)A device that changes one form of energy to another is called
(a) rheostat
(b) oscillator
(c) transducer
(d) varicap
(33) Aquadag is used in CRO to collect
(a) primary electron
(b) secondary electron
(c) both primary and secondary
(d) none of above
(34) A vertical amplifier for CRO can be designed for
(a) only a high gain
(b) only a broad bandwidth
(c) a constant gain time bandwidth product
(d)all of the above
(35) One of the following is active transducer
(a) Strain gauge
(b) Selsyn
(c) Photovoltic cell
(d) Photo emissive cell
(36) The dynamic characteristics of capacitive transducer are similar to those of
(a) low pass filter
(b) high pass filter
(c) band pass filter
(d) band stop filter
(37) Thermocouples are
(a) passive transducers
(b) active transducers
(c) both active and passive transducers
(d) output transducers
(38) The size of air cored transducers as compare to iron core counter part are
(a) bigger
(b) smaller
(c) same
(39) From the point of view of safety, the resistance of earthing electrode should be:
(a) low
(b) high
(c) medium
(d) the value of resistance of electrode does not effect the safety
(40) In CRT the focusing anode is located
(a) between pre accelerating and accelerating anodes
(b) after accelerating anodes
(c) before pre accelerating anodes
(d) none of above
(41) Which transducer converts heat energy into electrical energy
(a) I. V. D. T.
(b) thermocouple
(c) photoconductor
(d) none of the above
(42) Which of photoelectric transducer is used for production of electric energy by converting solar energy
(a) photo emission cell
(b) photo diode
(c) photo transistor
(d) both (b) and (c)
(43) Which of the following instruments consumes maximum power during measurement?
(a) induction instruments
(b) hot wire instruments
(c) thermocouple instruments
(d) electrodynamometer instruments
(44) Which of the following meters has the best accurancy
(a) moving iron meter
(b) moving coil meter
(c) rectifier type meter
(d) thermocouple meter
(45) The function of the safety resistor in ohm meter is to
(a) limit the current in the coil
(b) increase the voltage drop across the coil
(c) increase the current in the coil
(d) protect the battery
(46) Which of the following instruments is free from hysteresis and eddy current losses?
(a) M.l. instrument
(b) electrostatic instrument
(c) electrodynamometer type instrument
(d)all of these
(47) The dielectric loss of a capacitance can be measured by
(a) Wien bridge
(b) Owen bridge
(c) Schering bridge
(d) Maxwell bridge
(48) Reed frequency meter is essentially a
(a) recording system
(b) deflection measuring system
(c) vibration measuring system
(d) oscillatory measuring system
(49) In measurements made using a Q meter, high impedance elements should preferably be connected in
(a) star
(b) delta
(c) series
(d) parallel
(50) A digital voltmeter measures
(a) peak value
(b) peak-to-peak value
(c) rms value
(d) average value
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Network/ Transmission 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section C - Network Filters and Transmission Lines
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
Section C - 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
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Communication Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section B - Communication
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
SECTION: B Communication
(1) The most common modulation system used for telegraphy is
(a) FSK
(b) PSK.
(c) PCM
(d) single tone modulation
(e) Two tone modulation
(2)VSB is an abbreviation of vestigal sideband, is derived by filtering
(a) DSB
(b) AM
(c) either (a) or (b)
(d) PM
(3) The Hartely law states that
(a) The maximum rate of information transmission depends on the depth of modulation
(b) The maximum rate of information depends on the channel bandwidth.
(c) Only binary codes may be used
(d) Redundancy is essential
(4) The FM signal with, a modulation index mf is passed through a frequency tripler. The wave in the output of the tripler will have a modulation index of
(a) mf/9
(b) mf/3
(c) mf
(d) 3 mf
(e) 9mf
(5) In high power AM transmission, modulation is done at
(a) Buffer stage
(b) Oscillator stage
(c) RF power stage
(d) If stage
(6) Companding is used
(a) In delta modulator to combat noise
(b) To limit amplitude in PCM transmitters.
(c) In PWM for working it with TDM
(d) To protect small signals in PCM from quantizing distortion
(e) In PCM to reduce the SNR
(7) In PCM system the SNR of the output signal increases
(a) Inversely with bandwidth
(b) Exponential with bandwidth
(c) With rate of sampling
(d) At low frequencies only
(8) Armstrong modulator generates
(a) Phase modulated signal
(b) Frequency modulated signal
(c) Both of these
(d) Pulse code modulated signal
(e) AM and PCM signals
(9) A Klystron is a cavity acting as buncher and catcher is used as microwave tube for
(a) Guiding waves
(b) Velocity modulation
(c) frequency modulation
(d) impedance matching
(e) All of these
(10) Easily adjustable tuning component in a waveguide is
(a) plunger
(b) plunger and stub
(c) screw
(d) both (a) and (c)
(e) both (b) and (c)
(11) A ferrite is
(a) A non-conductor with magnetic properties
(b) A conductor with magnetic properties
(c) A semiconductors
(d) An insulator which attenuates magnetic fields
(e) A compound with good conductivity.
(12) Vacuum tubes eventually fail at microwave frequencies because of their
(a) Inter electrode capacitance
(b) Small series inductance
(c) Large shunt capacitance
(d) Short transit time
(e) Increased noise figure
(13) The biggest disadvantage the IMP ATT diode has is its
(a) Low Efficiency
(b) high noise
(c) Low BW
(d) inability to provide pulse operation
(e) low power handling ability
(14) In AM transmission the frequency, which is not transmitted is
(a) carrier frequency
(b) audio frequency
(c) upper side frequency
(d) lower side frequency
(15) FM broadcast band lies in
(a) VHF
(b) UHF
(c) SHF
(d) HF
(16) Automatic gain control is used
(a) to maintain the tuning correct
(b) to reduce the voltage of loud passage of music
(c) to maintain the same amount of output, when stations of different strength are received
(d) to increase the amplification at high frequencies
(17) The modulation system inherently is most noise resistant in
(a) SSB suppressed carrier
(b) FM
(c) PPM
(d) PCM
(18) In practical waveguide act as
(a) low pass filter
(b) high pass filter
(c)band pass filter
(d)band stop filter
(19) The antenna efficiencies achieved in practice depend upon
(a) wave length
(b) impedance
(c) frequency
(d) none of above
(20) The process of compressing the digital codes at the transmitter and then expanding them back to their original form at receiver is known as
(a) Quantizing
(b) companding
(c) step sizing
(d) modulation
(21) Digital transmission efficiency is given by
(a) information bits/total bits
(b) total bits/information bits
(c) redundant bits/information bits
(d) none of the above
(22) The speed of BRI ISDN interface is
(a) 2B + D
(b) 2D + B
(c) 30B + D
(d) 30D + B
(23) Which of the following is not a microwave generation source?
(a) Klystron
(b) Magnetron
(c) TWT
(d) Diode
(24) A signal of maximum frequency of 1 KHz is sampled at Nyquist Rate. The interval between two successive samples is:
(a) 50 micro seconds
(b) 100 micro seconds
(c) 500 micro seconds
(d) 1000 micro seconds
(25) In order to get back the original signal, it is necessary to use:
(a) low pass filter
(b) high pass filter
(c) band pass filter
(d) band reject filter
(26) Man made noise id caused by:
(a) Solar eruptions
(b) Distant Stars
(c) Lightning Discharges
(d) Arc discharge in electric machines
(27) At microwave frequencies, the size of antenna becomes
(a) very large
(b) large
(c) small
(d) very small
(28) Due to curvature of earth, microwave repeaters are placed at distance of about
(a) l0 Km
(b) 50 Km
(c) 200 Km
(d) 500 Km
(29) For handling large microwave power, the best medium is
(a) coaxial line
(b) rectangular waveguide
(c) stripline
(d) circular wave guide
(30) An attenuator is used with TWT to
(a) prevent oscillations
(b) increase gain
(c) prevent saturation
(d) help bunching
(3l) TWT is basically
(a) an oscillator
(b) tuned amplifier
(c) wideband amplifier
(d) an audio amplifier
(32) The negative resistance in Gunn diode is due to
(a) electron transfer to a less mobile energy level
(b) high reverse bias
(c) electron domain formation at the junction
(d) tunneling across the junction
(33) Which of the following sinusoidal oscillator is preferred for microwave frequencies?
(a) resonant circuit oscillator
(b) RC phase shift oscillators
(c) negative resistance oscillators
(d) all of the above
(34) When electromagnetic waves are propagated in a waveguide
(a) they travel along the walls of the waveguide
(b) they travel through the dielectric without touching the walls
(c) they are reflected from the walls but do not travel along the walls
(d) none of above
(35) Wave guides are generally made of
(a) Cast iron or steel
(b) White metal or gun metal
(c) bronze or aluminium
(d) plastic or bakelite
(36) The cut off frequency of a wave guide means
(a) lower frequencies will not be propagated
(b) it determines the dimensions of the wave guide
(c) frequency at which zero transmission takes place
(d) None of above
(37) In case of matched load
(a) Transmission is zero
(b) reflection is zero
(c) reflection is unity
(d) transmission is equivalent to reflection
(38) In an AM wave with 100% modulation, the carrier is suppressed. The percentage of power saving will be
(a) 100%
(b) 50%
(c) 25%
(d) 66.7%
(39) The function of AM detector circuit is
(a) to rectify the input signal
(b) to discard the carrier
(c) to provide the audio signal
(d) All of the above
(40) In FM, the noise can be further decreased by
(a) decreasing deviation
(b) increasuig deviation
(c) keeping deviation constant
(d) none of these
(41) In PPM, message resides in
(a) Pulses
(b) time location of pulse edges
(c) none of these
(42) Which of the following pulse systems is preferred for communication in presence of noise?
(a) PAM
(b) PDM
(c) PPM
(d) none of above
(43) Which of the following pulse systems requires higher bandwidth
(a) PAM
(b)PDM
(c)PPM
(d)none of these
(44) The audio frequency range lies between
(a) 20 to 20,000 Hz
(b) 20 to 20,000 KHz
(c) 400 to 8,000Hz
(d) 500 to 5,000 Hz
(45) Maximum undistorted power output of a transmitter is obtained when its modulation is:
(a) more than 100%
(b) 100%
(c) less than 100%
(d) 50%
(46) The AGC voltage in a radio receiver is proportional to
(a) the amount of modulation
(b) the amplitude of audio signal
(c) the amplitude of IF carrier
(d) none of these
(47) An FM transmitter has maximum frequency deviation of 75 KHz and reproduces audio signal up to 15 KHz. Minimum channel width required, in KHz is
(a) 180
(b) 120
(c) 90
(d) 60
(48) With 100% modulation, ratio of side band power to total power transmitted in an amplitude modulated wave is
(a) 2/3
(b) l/3
(c) l/2
(d) l/4
(49) To increase the Q factor of an induction, it wound with
(a) thicker wire
(b) thinner wire
(c) longer wire
(d) wire with heavy insulation
(50) Power factor of a purely resistive circuit is:
(a) zero
(b) one
(c) 0.5
(d) infinity
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Electrical Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section A - Electrical
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
SECTION A - 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
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Micro Processors Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section F - Microprocessors
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
1. A 32-bit processor has
(a) 32 registers
(b) 32 I/O devices
(c) 32 Mb of RAM
(d) a 32-bit bus or 32-bit registers
2. Clock speed is measured in
(a) bits per second
(b) Hertz
(c) bytes
(d) baud
3. A 20-bit address bus allows access to a memory of capacity
(a) 1 MB
(b) 2 MB
(c) 4 MB
(d) 8 MB
4. A microprocessor contains
(a) most of RAM
(b) most of ROM
(c) peripheral drivers
(d) most of the control and arithmetic logic functions of computer
5. Which of the following is NOT a type of processor?
(a) PowerPC
(b) Motorola 8086
(c) Motorola 68000
(d) Intel Pentium
6. If interrupt arrives on the three lines INTR, RTS 6.5 and RTS 7.5, which of them will the 8085 processor acknowledge?
(a) INTR
(b) RTS 6.5
(c) RTS 7.5
7. The Intel 8086 processor is
(a) 8-bit
(b) 16-bit
(c) 32-bit
(d) 64-bit
8. An assembly language instruction
(a) always has a label
(b) always takes at least one operand
(c) always has an operation field
(d) always modifies the status register
9. An interrupt instruction
(a) causes an unconditional transfer of control
(b) causes a conditional transfer of control
(c) modifies the status register
(d) is an I/O instruction
10. Programs are written in assembly language because they
(a) run faster than High-level language
(b) are portable
(c) easier to write than machine code programs
(d) they allow the programmer access to registers or instructions that are not usually provided by a High-level language
11. Given that the subprogram putc displays the character in al, the effect of the following instruction is -
mov al, ‘c’
sub al, 2
call putc
(a) display 2
(b) display ‘c’
(c) display ‘a’
(d) display a blank
12. The result of mov al, 65 is to store
(a) store 0100 0010 in al
(b) store 42H in al
(c) store 40H in al
(d) store 0100 0001 in al
13. Microprocessor is also often called a
(a) Chip
(b) Resistor
(c) Capacitor
(d) Transistor
14. A microprocessor’s program counter has
(a) the digital value of the data
(b) the address of an instruction
(c) the address of data
15. Which of the following is a math co-processor?
(a) 8085
(b) 8086
(c) 8087
(d) 8088
16. Interrupts are classified as
(a) Hardware interrupts
(b) Software interrupts
(c) Hardware interrupts and Software interrupts
(d) none of the above
17. The system bus is made up of
(a) data bus
(b) data bus and address bus
(c) data bus and control bus
(d) data bus, control bus and address bus
18. The memory address register is used to store -
(a) data to be transferred to memory
(b) data that has been transferred from memory
(c) the address of a memory location
(d) an instruction that has been transferred from memory
19. When an interrupt occurs, the processor completes the current ___________ before jumping to the interrupt service subroutine
(a) microinstruction it is executing
(b) instruction it is executing
(c) macro it is executing
(d) subroutine it is executing
20. A microprocessor is a processor with a reduced
(a) instruction set
(b) power requirement
(c) MIPS performance
(d) none of the above
21. A scheme in which the address specifies which memory word contains the address of the operand, is called
(a) Immediate addressing
(b) Based addressing
(c) Direct addressing
(d) Indirect addressing
22. Processor gets the address of the next instruction to be processed from
(a) Instruction register
(b) Instruction counter
(c) Program counter
(d) Program register
23. Fetch operations are not required in
(a) Immediate addressing
(b) Register addressing
(c) Direct addressing
(d) Indirect addressing
24. What is meant by Maskable interrupts?
(a) An interrupt that can be turned off by the programmer.
(b) An interrupt that cannot be turned off by the programmer.
(c) An interrupt that can be turned off by the system.
(d) An interrupt that cannot be turned off by the system.
25. Which interrupts are generally used for critical events such as Power failure, Emergency, Shut off etc.?
(a) Maskable interrupts
(b) Non-Maskable interrupts
(c) none of the above
26. Which microprocessor accepts the program written for 8086 without any changes?
(a) 8085
(b) 8087
(c) 8088
27. How many memory locations are required to store the instruction LXI H, 0800H in an 8085 assembly language program?
(a) 1
(b) 2
(c) 3
(d) 4
28. How many memory fetches (including instruction fetch) are required to execute the instruction LXI H, 0800H in an 8085 assembly language program?
(a) 1
(b) 2
(c) 3
(d) 4
29. MPU stands for
(a) Multi-Processing Unit
(b) Micro-Processing Unit
(c) Mega-Processing Unit
(d) Major-Processing Unit
30. Which of the following is not possible by a microprocessor?
(a) Reading from Memory
(b) Writing into Memory
(c) Reading from Input port
(d) Writing into Input port
31. In which microprocessor does the concept of pipeline first introduced?
(a) 8086
(b) 80286
(c) 80386
(d) 80486
32. LSI stands for -
(a) Large Size Instruction
(b) Large Scale Instruction
(c) Large Size Integration
(d) Large Scale Integration
33. Which of the following is true about pseudo code?
(a) A machine language
(b) An assembly language
(c) A high level language
(d) none of the above
34. The macro processor must perform
(a) recognize macro definitions and macro calls
(b) save the macro definitions
(c) expand macro calls and substitutes arguments
(d) all of the above
35. A 32 bit microprocessor has the word length equal to
(a) 1 byte
(b) 2 byte
(c) 4 byte
(d) 8 byte
36. The TRAP interrupts mechanism of the 8085 microprocessor
(a) execute an instruction supplied by an external device through the INTA signal
(b) execute an instruction from memory location 20H
(c) executes a NOP
(d) none of the above
37. What are the states of the Auxiliary carry (AC) and Carry flag (CY) after executing the following 8085 program?
MVI H, 5DH
MVI L, 6BH
MOV A, H
ADD L
(a) AC=0 and CY=0
(b) AC=1 and CY=1
(c) AC=1 and CY=0
(d) AC=0 and CY=1
38. Contents of register A after the execution of the following 8085 microprocessor program is
MVI A, 55H
MVI C, 25H
ADD C
DAA
(a) 7AH
(b) 80H
(c) 50H
(d) 22H
39. Which of the following is a 16-bit micro processor?
(a) Motorola 6800
(b) Intel 8085
(c) Intel 8086
(d) Zilo 80
40. The Intel Pentium Pro microprocessor uses 36 address lines to access memory. What is the maximum memory that it can support, in gigabytes?
(a) 16
(b) 32
(c) 64
(d) 128
41. Out of the following which is not the flag in 8085 microprocessor
(a) Counter flag
(b) Carry flag
(c) Zero flag
(d) Parity flag
42. What is a basic element of Memory?
(a) Transistor
(b) Flip-flop
(c) Gate
(d) none of the above
43. Which group of instructions do not affect the flags?
(a) Arithmetic operations
(b) Logic operations
(c) Data transfer operations
(d) Branch operations
44. DMA stands for
(a) Direct Memory Allocation
(b) Distinct Memory Allocation
(c) Direct Memory Access
(d) Distinct Memory Access
45. In RST interrupts, RST stands for
(a) Repeat Start Test
(b) Restart
(c) Start
46. Which interrupt has the highest priority?
(a) TRAP
(b) RST 6
(c) RST 6.5
(d) INTR
47. In 8085 microprocessor with memory mapped I/O
(a) I/O device have 8-bit addresses.
(b) I/O devices are accessed using IN and OUT instructions.
(c) arithmetic and logic operations can be directly performed with the I/O data.
(d) there can be a max of 256 input devices and 256 output devices.
48. A microprocessor -
(a) reads instructions from memory
(b) communicates with I/O devices
(c) controls the timing of information flow
(d) all of the above
49. An instruction consists of
(a) Data and Address
(b) Register and Memory
(c) Opcode and Operand
(d) Input and Output
50. If the 8085 adds 87H and 79 H, which of the following flags will become 1
(a) Zero flag and Auxiliary Carry flag
(b) Zero flag and Carry flag
(c) Carry flag and Auxiliary Carry flag
(d) none of the above
More in TTA Previous Papers 2007 Series
- BSNL TTA Question Paper: Electrical Specialization 2007
- BSNL TTA Question Paper: Computers Specialization 2007
- BSNL TTA Question Paper: Micro Processors Specialization 2007
- BSNL TTA Question Paper: Instruments and Measurement Specialization 2007
- BSNL TTA Question Paper: Network/ Transmission 2007
- BSNL TTA Question Paper: Communication Specialization 2007
- BSNL TTA Question Paper: Control Systems Specialization 2007
BSNL TTA Question Paper: Computers Specialization 2007
Exam Name:
TTA (Telecom Technical Assistant)
Specialization:
Section G - Computers
Conducted By:
BSNL (Bharat Sanchar Nigam Limited)
Conducted In:
December 2007
Number of Questions:
50
Maximum Marks:
250
Time Allowed:
90 Minutes
Negative Marking:
Yes
Type of Questions:
Objective Type (Multiple Choice)
BSNL TTA Specialization (Computers) Question Paper 2007
1. What is the name of the software that allows us to browse through web pages?
(a) Browser
(b) Mail Client
(c) FTP Client
(d) Messenger
2. What is the address given to a network called?
(a) System Address
(b) SYSID
(c) Process ID
(d) IP Address
3. Which one of the following is a valid DOS command?
(a) LIST *.*
(b) LIST???.???
(c) RECOVER A:
(d) RENAME A:SAMPLE.TXT C:TEST.DOC
4. All system settings in WINDOWS are stored in:
(a) CONTROL.INI
(b) MAIN.INI
(c) SYSTEM.INI
(d) SETTING.INI
5. Which number system is usually followed in a typical 32-bit computer?
(a) 2
(b) 10
(c) 16
(d) 32
6. Which of the following is not an output device:
(a) Printer
(b) Scanner
(c) Flat Screen
(d) Touch Screen
7. A microprocessor is a processor with reduced
(a) instruction set
(b) power requirement
(c) MIPS performance
(d) none of the above
8. Which of the following is not an output of an assembler?
(a) executable program
(b) source listing with line numbers and errors
(c) a symbol table
(d) object program
9. Which layer of OSI model is responsible for routing and flow control:
(a) Presentation
(b) Transport
(c) Network
(d) Data Link
10. Arrays are passed as arguments to a function by
(a) value
(b) reference
(c) both a and b
(d) none of the above
11. Array is:
(a) linear data structure
(b) non-linear structure
(c) none of the above
12. A data structure in which elements are added and removed from only one end, is known as:
(a) Array
(b) Stack
(c) Queue
(d) None of the above
13. A diamond-shaped box in an Entity-Relationship diagram refers to:
(a) Entity
(b) Relationship
(c) Attribute
14. The principle means of identifying entities within an entity set is:
(a) Primary Key
(b) Record
(c) Attribute
(d) Tuple
15. Modem refers to:
(a) Modulator
(b) Modulation
(c) Demodulator
(d) Modulator and Demodulator
16. C language is available for which of the following Operating Systems?
(a) DOS
(b) Windows
(c) Unix
(d) All of the above
17. Which of the following have the fastest access time?
(a) Magnetic Tapes
(b) Magnetic Disks
(c) Semiconductor Memories
(d) Compact Disks
18. DMA stands for:
(a) Direct Memory Allocation
(b) Distinct Memory Allocation
(c) Direct Memory Access
(d) Distinct Memory Access
19. Array subscripts in C always start at:
(a):1
(b) 0
(c) 1
(d) Value provided by user
20. Which type of commands in DOS needs additional files for their execution?
(a) Batch Commands
(b) Internal Commands
(c) External Commands
21. Which of the following statements in regard to Directories is false?
(a) Directories can exist inside directories
(b) The root directory is always at the highest level
(c) Directories with files can be deleted
(d) Directories cannot be renamed
22. It is better to buffer a table when
(a) When a table is read infrequently
(b) When a table is linked to check tables
(c) When a table is read frequently and the data seldom changes
(d) When a single record is to be picked up
23. The Operating System is responsible for:
(a) Controlling peripheral devices such as monitor, printers, disk drives
(b) Provide an interface that allows users to choose programs to run and to manipulate files
(c) Manage users’ files on disk
(d) All of the above
24. A company whishes to connect two sites in different parts of the country together. It is decided to use the telephone system. What device should be connected to the fileservers on each site?
(a) Router
(b) Modem
(c) Switch
(d) Hub
25. What is a file server?
(a) A computer that performs a service for other computers
(b) A computer that controls the printers on the network
(c) A computer that stores files that are created by network users
26. What is the Protocol used for the Internet?
(a) IPX/SPX
(b) NetBIOS/NetBEUI
(c) CDMA/CA
(d) TCP/IP
27. Which one of the following is not a Normal Forms (Normalization) rule with regards to the Relational Model?
(a) All fields within a table must relate to or directly describe the Primary Key.
(b) Repeating Groups must be eliminated from tables.
(c) Fields that can contain non-numeric data are to be removed and placed within their own tables with an associated Primary Key.
(d) Redundant data is to be eliminated by placing the offending fields in another table.
28. Choose the answer which best describes the term Primary Key:
(a) The Primary Key is a field that contains data that can be duplicated.
(b) The Primary Key is a field that contains data that is unique.
(c) The Primary Key is a field that is never associated with