BSNL TTA Mock Test

Please get the BSNL, Telecom Technical Assistant post exam paper so that I can check them easily and have idea about them?

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Feel free I will get the BSNL, Telecom Technical Assistant post exam paper so that you can have idea and go through it.

Here is the exam paper

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

BSNL, Telecom Technical Assistant post exam paper

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 any field in other tables.
(d) The Primary Key field is a concept used only in Microsoft Access.
29. Which technique is used to reduce the size of a file:
(a) Compression
(b) Decompression
(c) Encryption
(d) Decryption
30. BIOS stands for
(a) Binary Input Output Set
(b) Binary Input Output System
(c) Basic Input Output Set
(d) Basic Input Output System
31. A floppy disk is consisting of 40 tracks, each track contains 100 sectors, and the capacity of a
sector is 512 bytes, what is the approx. size of that disk?
(a) 1 MB
(b) 2 MB
(c) 4 MB
(d) 8 MB
32. What is the binary equivalent of a decimal number 68:
(a) 1000100
(b) 1100100
(c) 1000010
(d) 1000001
33. Assembly language to machine language translation is:
(a) One-to-One
(b) One-to-Many
(c) Many-to-One
(d) Many-to-Many
34. Maximum size of IP address is:
(a) 12 bits
(b) 24 bits
(c) 32 bits
(d) 48 bits
35. RAM stands for
(a) Read Access Memory
(b) Read After Memory
(c) Random Access Memory
(d) Random After Memory
36. What is the final value of sum?
main ()
{
int sum=1;
for(;sum<=9
printf(%d\n, ++sum);
}
(a) 9
(b) 10
(c) 11
(d) none of the above
37. If c is a variable initialized to 1, how many times the following loop be executed:
while(c>0 && c<60)
{
c++;
}
(a) 59
(b) 60
(c) 61
(d) none of the above
38. The declaration void fun(int) indicates the fun is a function which:
(a) has no arguments
(b) returns nothing
(c) both a and b
(d) none of the above
39. Out of the following which is not valid network topology:
(a) Bus
(b) Star
(c) Circle
(d) Tree
40. The overall logical structure of a database can be expressed graphically by:
(a) Data Flow Diagram
(b) Flow Chart
(c) Directed Graph
(d) Entity-Relationship Diagram
41. CARRY, in a half-adder, can be obtained using:
(a) OR gate
(b) AND gate
(c) EX-OR gate
(d) EX-AND gate
42. The memory that requires refreshing of data is:
(a) SROM
(b) DROM
(c) SRAM
(d) DRAM
43. The minimum number of bits required to represent numbers in the range:28 to +31 is-
(a) 5
(b) 6
(c) 7
(d) 8
44. Which bus carries information between processors and peripherals?
(a) Data bus
(b) Control bus
(c) Address bus
(d) Information bus
45. Which part of the computer perform arithmetic calculations?
(a) Control unit
(b) Registers
(c) ALU
(d) CPU
46. A gigabyte represents:
(a) 1 billion bytes
(b) 1000 kilobytes
(c) 230 bytes
(d) 10 megabytes
47. The minimum number of bits required to store the hexadecimal number FF is:
(a) 2
(b) 4
(c) 8
(d) 16
48. Cache memory enhances:
(a) memory capacity
(b) memory access time
(c) secondary storage capacity
(d) secondary storage access time
49. A UPS:
(a) increases the storage capacity of a computer system
(b) increases the processor speed
(c) provides backup power in the event of a power cut\
(d) none of the above
50. An RDBMS is a:
(a) Remote DBMS
(b) Relative DBMS
(c) Reliable DBMS
(d) Relational DBMS