The solved question paper for Telecom Technical Assistant (TTA) post exam for BSNL or Bharat Sanchar Nigam Limited is as follows:

BSNL Question Paper

Question .1 A house served by a 220V supply light, is protected by a 9-Ampere fuse. The maximum number of 60 W bulbs in parallel that can be turned on is
(a) 11
(b) 33
(c) 22
(d) 44
Answer: B
Question.2 A capacitor of 1 Q.4 μF initially charged to 10 V is connected across an ideal inductor of 0.1 mH. The maximum current in the circuit is
(a) 0.5 A
(b) 1 A
(c) 1.5 A
(d) 2 A
Answer: B
Question.3 An n-channel JFET has I Q.2 DSS = 1 μA & VP =–5V. The maximum trans conductance is
(a) gm = 0.4 milli mho
(b) gm = 0.04milli mho
(c) gm = 0.04 mho
(d) gm = 0.4 millimilli mho
Answer: D

Question.4 Silicon has a preference in IC technology because Q.5
(a) it is an indirect semiconductor
(b) it is a covalent semiconductor
(c) it is an elemental semiconductor
(d) of the availability of nature oxide SiO
Answer: D
Question.5 An analog voltmeter has a sensitivity of 10kΩ/volt. The galvanometer used in constructing the instrument will produce a full scale deflection when the current passed through it is
(a) 10 mA
(b) 20 mA
(c) 50 mA
(d) 100 μA
Answer: D
Question.6 The base to base resistance of a UJT is 6 K Ohm when the emitter current is zero. If B1 R = 3.6 K Ohm, the intrinsic stand off ratio is
(a) n = 0.66
(b) n = 0.6
(c) n = 6.0
(d) n = 3.6
Answer: B

Question.7 Transient signals can be observed using
(a) storage oscillocope
(b) sampling oscilloscope
(c) wave analyzer
(d) spectrum analayzer
Answer: A
Question.8 A power diode has lightly doped n type substrate sandwiched between heavily doped p and n regions
(a) to increase reverse breakdown voltage
(b) to reduce ohmic loss under forward bias
(c) to decrease switching time of the power diode
(d) to improve transient behaviour of the diode
Answer: D
Question.9 A P-controller is used to adjust the outer level of a tank in range of (0-10)m. The desired level is 5 m. The controller should fully close the valve, if level rises to 5.5 m and it should fully open the valve, if level falls to 4.5 m. What should be the % P-band?
(a) 1
(b) 5
(c) 7
(d) 10
Answer: D
Question.10 Some system architects do not find RISC instruction repertoire to be cost-effective because it
(a) result in large increase in programme size
(b) result in complex structure of microcode
(c) has been observed that an average compiler does not employ more than a limited subset of available instructions
(d) results in complex decoding of opcode filed resulting in longer execution time
Answer: A

Question.11 What addressing mode is used in the instruction RET?
(a) Direct
(b) Immediate
(c) Implicit
(d) Register-indirect
Answer: D
Question.12 The speed of an audio cassette tape in a cassette player is 5cm/ sec. If the maximum frequency that needs to be recorded is 20 KHz, the minimum spatial wavelength on the tape is
(a) 40 μm
(b) 25 μm
(c) 4 μm
(d) 2.5 μm
Answer: D
Question.13 In order to generate electron-hole pairs, the maximum wavelength of radiation for Silicon (Band gap = 1.1 eV) is
(a) 1.88 μm
(b) 1.68 μm
(c) 1.13 μm
(d) 1.54 μm
Answer: C

Question.14 Which of the following pairs of crystal structure possesses the same atomic packing density?
(a) simple cubic & body centred cubic
(b) body centred cubic & face centred cubic
(c) face centered cubic & hexagonal close packed
(d) body centred cubic & hexagonal close packed
Answer: C
Question.15 In a power transformer, the fundamental frequency of the hum arising due to magnetostriction is
(a) equal to the line frequecy
(b) double the line frequency
(c) 4 times the line frequency
(d) not related to the line frequency
Answer: B
Question.16 The polar bonds existing in III-V compound semicondutor, may be considered as equivalent to
(a) 1 ionic bond and 3 covalent bonds
(b) 1 ionic bond and 4 covalent bonds
(c) 2 ionic bonds and 2 covalent bonds
(d) 2 ionic bonds and 4 covalent bonds
Answer: A

Question.17 In a regenerative braking, which of the following is generally true?
(a) Back e.m.f. in the motor exceeds the applied voltage
(b) Back e.m.f. is less than the applied voltage
(c) Kinetic energy of the motor is dissipated in a resistance
(d) Kinetic energy of the motor is dissipated through free wheeling diode across the motor
Answer: A
Question.18 To distinguish between signals having very close values, we need
an instrument with
(a) high accuracy
(b) high resolution
(c) high sensitivity
(d) high linearity
Answer: B
Question.19 The trace on an oscilloscope continually moves to the right of the screen when
(a) the sweep is triggered.
(b) the sweep period is larger than the signal period.
(c) the sweep period is smaller than the signal period.
(d) there is no weep.
Answer: B

Question.20 An optical fiber cable laid underground has developed a discontinuity at a distance d from the source end. The fault can be located using the instrument
(a) Optical spectrum Analyzer (OSA)
(b) Optical Time Domain Reflectometer (OTDR)
(c) Optical Power Meter (OPM)
(d) Laser Diffractometer (LD)
Answer: B
Question.21 By which of these nicknames is Nagpur also known as?
(a) Diamond City
(b) Orange City
(c) Pink City
(d) City of Lakes
Answer: B
Question.22 Which of these is a traditional Sikh Maritial Art named after a stick used to practice sword fighting?
(a) Gatka
(b) Hola Mohalla
(c) Shakhl
(d) Kakaar
Answer: A
Question.23 Maulana Abul Kalam Azad’s Birthday on 11 November is celebrated in India as what?
(a) National Education Day
(b) National Integration Day
(c) National Minority Day
(d) National Sports Day
Answer: A

Question.24 At which of the following places Diesel Component Works is established?
(a) Jamshedpur
(b) Patiala
(c) Perambur
(d) Varanasi
Answer: B
Question 25. The All Women Expedition Team of the Indian Air Force which scaled the Mount Everest some time back was headed by
(a) Sqn. Ldr. D. Panda
(b) Sqn. Ldr. Nirupama Pandey
(c) Flt. Lt. Nivedita Choudhary
(d) Flt. Lt. Rajika Sharma
Answer: B
Question.26 The zero flag of 8085 microprocessor is to be set keeping the content of the accumulator unchanged. Which instruction is to be used?
(a) MOV A,A
(b) ANI 00H
(c) XRA A
(d) CMP A
Answer: D

Question.27 To establish a communication between 8085 microprocessor and 8255 Programmable Peripheral Interface chip. The status of the chip select input would be
(a) TRISTATE
(b) HIGH
(c) LOW
(d) DON’T CARE
Answer: C
Question.28 Which flag does not change by the execution of the instruction DCR B in 8085 microprocessor ?
(a) Parity
(b) Carry
(c) Zero
(d) Sign
Answer: B

Question.29 Suppose that data items, numbered 1, 2, 3, 4, 5 and 6 come in the input stream in this order. By using a queue, which of the following rearrangement can be obtained in the output order ?
(a) 1 2 6 4 5 3
(b) 2 4 3 6 5 1
(c) 4 2 1 3 5 6
(d) 1 2 3 4 5 6
Answer: D
Question.30 For an antenna to be frequency-independent, it should expand or contract in proportion to the
(a) gain
(b) directivity
(c) wavelength
(d) impedance
Answer: D