LDC JE Exam Questions - PDF

## Question Bank 1. The most widely used universal gates are: - OR' and AND gates - NOR and NANO gates - NOR and AND Gates - NANO and OR gates 2. Frequencies allotted for Tetra based communication systems are _____ bands. - 260-300 MHz & 410-430 MHz - 380-400 MHz & 410-430...

## Question Bank 1. The most widely used universal gates are: - OR' and AND gates - NOR and NANO gates - NOR and AND Gates - NANO and OR gates 2. Frequencies allotted for Tetra based communication systems are _____ bands. - 260-300 MHz & 410-430 MHz - 380-400 MHz & 410-430 MHz - 260-300 MHz & 380-400 MHz - 160 to 260 MHz and 290 to 390 MHz 3. Universal Emergency Communication (UEC) Operates on _____ frequency. - 196.23 - 456.56 MHz - 260.2 - 300.45 MHz - 159.6-162.45 MHz - 146.2-151.45 MHz 4. Full form of TETRA is _____. - Telecom terrestrial Radio - Terrestrial Trunk Radio - Train emergency trunk Radio - Telecom testing Radio 5. The error of an instrument is normally given as a percentnce of _____. - Mean value - Measured value - RMS value - Full scale value 6. The basic A to D converter used in a digital volt meter is _____. - Phase converter - Current converter - Frequency converter - voltage to time converter 7. A voltmeter using a 50 micro ampere meter has a sensitivJ:·, of _____. - 20 Kilo ohms per volt - 20 00 ohms per volt - 20 Mega ohms per volt - 50 Kilo ohms per volt 8. An instrument has a sensitivity of 1000 ohms per volt On 100 volt scale the instrument will have internal resistance of _____. - 1 Mega ohms - 10•ohms - 1000 ohms - 10,000 ohms 9. If the voltmeter resistance is increased the error in the reading given by the voltmeter will be _____. - Increase - Increase or decrease depending pon the value of measurement - Decrease - Independent of voltmeter resistance 10. A digital volt meter has 4 and 1/2 digit display, the one volt range can be read upto _____. - 9999 - 0.19999 - 9.99 - 1.999 11. CCITT stands for _____. - Consultative committee for International Telephony and Telegraphy - Consultative committee for Indian Telephony and Telegraphy - Consultative committee for Indian Telecommunication and Telegraphy - Consultative committee for International Telephony and Telecommunication 12. Which of the following meter has a linear scale. - Hot wire meter - Thermocouple meters - PMMC meter - Moving Iron meters 13. In a measurement system the transducer is the - Signal conditioning device - Processing device - Input element - Output element 14. ITU stands for _____. - International Telegram Union - International Telecommunication Union - Indian Telecommunication Union - International Telephony Union 15. 33dBm is equal to _____. - 4 watts - 2 watts - 6 watts - 8 watts 16. A Megger is usually _____. - A moving iron type instrument - Electrostatic type instrument - Moving coil type instrument - hot wire type instrument 17. Transmission measuring sets are used for measuring _____. - Return loss - Signal levels and transmission loss - Insertion loss - Signal levels & Transmission loss, Return loss & Insertion loss 18. OSPF stands for _____. - Open shortest path first - Open space path first - Open shortest path field - None of the above 19. The instrument used normally to check insulation is - Megger - Tong Tester - Multimeter - AVO meter 20. Data Network Analyzer is basically a. - Protocol Analyzer - Packet Analyzer - Protocol Analyzer, Packet Analyzer & Sniffer - Sniffer 21. Spectrum analyzer examines the Spectral composition of EM waves consisting of the following wave forms. - Electrical - Optical - Electrical, Optical & their power wavefonns - Power 22. Spectrum analyzer are used to examines the following characteristics of unknown signals. - Carrier levels, Side bands & Hannonics & Phase Noise - Side bands and Hannonics - Phase Noise - Carrier levels 23. Frequency counters used for Microwave applications are of _____. - Reciprocal method type - Direct method type - Heterodyne method type - None of above 24. Over Head lines are not fit for Tele communication circuits in RE area because of - High cross talk - Interference of Induced voltage by 25kv - Conductors do not have insulation - Conductors are thick 25. The purpose of twisted pair cables in telecom cables is - To reduce cross talk - Ease in manufacturing - To avoid signal loss - To give strength 26. At what distance condenser joint is done in a loading section of 6 quad cable - 1220mtrs - 1200mtrs - 100Omtrs - 915mtrs 27. What is the purpose of loading in an underground telecom cable - To increase attenuation - To decrease cross talk - To reduce transmission loss - To reduce noise 28. What is the length of loading section for a 6quad cable - 1900mtrs - 1830mtrs - 2000mtrs - 2500mtrs 29. The Unbalance in capacitive couplings of quad cable causes _____. - Distortion - Attenuation - Cross talk - Noise 30. Unbalance of Earth couplings in VF circuits causes _____. - Cross talk - Noise - Attenuation - Distortion 31. The Capacitance unbalance between side circuit 2 of quad number 1 with respect to side circuit 1 of quad number 1 is _____. - K11 - K9 - K10 - K12 32. What is the maximum capacitance unbalance permitted in a loading section - 30pf - 20pf - 10pf - 40pf 33. Two number of 8 Ohms resister connected in series, the resulta_nt value is. - 8 Ohms - 16 Ohms - 4Ohms - 64Ohms 34. Two number of 8 Ohms resister connected in parallel, the resultant value is. - a.ohms - 16 Ohms - 4Ohms - 64 Ohms 35. Telecom switch board cables are used for - lndoor telecom wiring - Underground telecom wiring - Electrical switch board wiring - Outdoor telecom wiring 36. The characteristic·impedance of a switch board cable is - 1120 ohms - 600 ohms - 470-ohms - 500 ohms 37. Expand UTP cable - Unshielded twisted pair - Unscreened twisted pair - Unused twisted pair - Unusual twisted pair 38. In general, CAT cables are connected with. type of connectors. - RJ11 - RJ9 - RJ45 - RJ15 39:ln STP cables is used as screen. - Aluminium wires - Aluminium sheath - Aluminium foil - Copper sheath 40. The co-axial cables usual impedance shall be or Ohms - 40-50 or 70-80 - 20-40 or 30-40 - 40-60 or 70-100 - 40-60 or 70-90 41. RG 8 cable can be used upto the length of - 600mtrs - 800mtrs - 400mtrs - 500mtrs 42. What is the colour code of 37th pair in a 50 pair switch tioard cable. - Blue & red - Orange & red - Slate & white - Green & red 43. RIP stands for. - Routing Information Protocol - Resolution Information Protocol - Real-Time Information Protocol - Routine Information Process 44.UTP cable that transmits up to 16Mbps is _ - Cat2 - Cat1 - Cat3 - Cat4 45. TCP/IP stands for. - Transmission Communication Process/ Internet Protocol - Transmission Control ProtocoV Internet Protocol - Transmission Control Process/ Internet Protocol - None of the above 46. Purpose of rip cord in a switch board cable is - To route the cable through pipes - To uncoil the cable - To remove the insulation of the conductor - To facilitate the removal of PVC sheath 47. Expand PIJF _ - Polyethylene insulated jelly filled - Polymer insulated jelly filled - Polyvinyl insulated jelly filled - Polyester insulated jelly filled cable 48. ROSO spec. for PIJF telephone Cable is _ - TEC Spec.No:GR/WIR/06/03 of March 2002 - IS 434-Part-1/1964 - IS-694-Part/1964 - IRS-TC:41/97 49. The colour code of pair number 16 in a 20 pair PIJF cable _ - Black & yellow - Blue & yellow - Blue & black - Black & slate 50. In 20 pair PIJF cable, conductor insulation main colours are _____ and mate colours are _____. - 3 & 5 - 4 & 5 - 5 & 4 - 6 &4 51. The number of units in 20 pair cable are - 4 - 3 - 5 - 6 52. The number of units in 50 pair cable are - 4 - 6 - 5 - 2 53. The number of units in 100 pair cable are - 6 - 4 - 7 - 5 54. Number of binding tapes used for identifying each unit in PIJF pair cable are _____. - 4 - 6 - 3 - 5 55. Entry of moisture/water is prevented by _____ in PIJF cable - GI armour - Polythene sheet - Alunimium sheath - Jelly 56. Purpose of amour in U/G cable is - Provides screening - Prevents the entry of water - Prevents the entry of moisture - Mechanical strength 57. Loop resistance of 0.51 mm conductor dia PIJF cable is _____ - 192 ohms - 194 ohms - 180 olims - 184 ohm 58. The induction by A.C traction system in Telecom circuits is due to _____ and _____ couplings - Electrostatic and electromagnetic - Electric and magnetic - Electrostatic and galvanic - Electromagnetic and transformer 59. Cumulative build up of induced voltage in U/G telecom cable is prevented by - Isolation transforn\ers - Step down transformers - Matching transformers - Current transformers 60. Psophometric voltage in the telecommunication circuits should not exceed _____ mV. - 3mV - 4mV - 2mV - 5mV 61. The screening factor of Aluminium sheath/screen is always _____ than unity. - Equal to - Less - None of above 62. Isolation transformers are used to _ - For reducing noise - For impedance matching - To reduce Induced voltage due to catenary - For balancing of circuits 63. Under normal conditions of traction power system the longitudinally induced voltage in the telecommunication cable should not exceed _____ v - 60 V - 90 V - 70 V - 80 V 64. Maximum permissible induced voltage in an U/G·telecom cable is _____ - 160 V - 150 V - 170V - 140 V 65. Isolation transformers are introduced at a regular intervals of approximately _____ Kms - 19 kms - 17 kms - 20 kms - 10 kms 66. OTDR stands for. - Optical Time Domain Reflectometer - Optional Time Domain Reflectometer - Optical Time Distance Reflectometer - None of the above 67. Isolation transformers are provided at - cable huts - At EC sockets - Repeater - Test room 68. The Transmission loss in·0.9 mm conductor dia quad cable is _____ db/km - 0.25 - 0.69 - 0.63 - 0.38 69. Wire system in U/G cable is used because of _____. - Using cable huts in between - For future usage - Amplifiers are used - To have two wires as stand by 70. ROSO specification of 4/6 PIJF quad catile of0.9 mm dia conductor is - IRS:TC: 30/2005 ver.2 - IRS:TC: 50/2005 ver.2 - IRS:TC: 40/2005 ver.2 - IRS:TC: 30/2015 ver.2 71. ROSO specification of 4/6 PIJF quad cable of 1.4 mm dia conductor is - IRS:TC 50/2005 ver.2 - IRS:TC: 30/2005 ver.2 - RDSO/SPN/TC/72-07 - RDSO/SPN/TC/82-07 72. 1.4 mm dia conductor 4/6 quad cable is used when the distance between the block Stations is - More than 15kms - More than 25kms - More than 30kms - More than 10kms 73. The insulation resistance between each conductor in a quad shall not be less than - 500 MOhms/km - 400 MOhms/km - 100 M Ohms/km - 200 MOhms/km 74. Purpose of Poly Aluminium sheath in a quad cable is - To prevent the entry of moisture - To provide screening - To protect the conductors from damage - To reduce induced voltages 75. The colours of conductors of quad no 5 in 6 quad cable is _ - Blue, white, red, slate - Green, white, red, slate - Black, white, red, slate - Yellow, white, red, slate 76. The resistance of conductor in a quad cable is _ - 58 Ohms/km - 26 Ohms/km - 56 Ohms/km - 28 Ohms/km 77. The characteristic impedance of a 6 quad cable is _ - 1120 Ohms - 56 Ohms - 600 Ohms - 470 Ohm 78. What is the minimum distance to be maintained between the OHE masts and the cable - 6.00mtrs - 5.00mtrs - 5.75mtrs - 6.75mtrs 79. The normal depth of the trench for Telecom Cable is _ - 1.8 metres - 1.5 metres - 1 metres - 2 metres 80. The standard drum length of 4/6 quad cable is. . - Two kms - 460 mtrs - One kms - 600 mtrs 81. Telecom cable shall be laid in _____ pipes for a length of _____ on 1atther side ofTSS - HOPE & 200 mtrs - RCC pipes & 300mtrs - Troughs & 200 mtrs - GI pipes & 200 metres 82. A cable reserve of ______ meters to be provided at every joint loop - 3 mtrs - 2 mtrs - 5 mtrs - 4 mtrs 83. The widely used cable laying method for U/G cables is, - Laying in PVC pipes - Laying direct in the ground - Drawing through ducts - Laying solid 84. On each side of minor bridge a cable reserve of ______ meters to be provided - 6 mtrs - 7 mtrs - 5 mtrs - 4 mtrs 85. On each side of major girder bridge a cable reserve of ______ meters to be provided - 10 mtrs - 5 mtrs - 15 mtrs - 20 mtrs 86. The cable route indicators are to be placed at every ______ meters on normal path - 100 mtrs - 60 mtrs - 70 mtrs - 50 mtrs 87. The derivation cable used in 4/6 quad cable system is _ - 4 quad cable - SW8Dcab - 6 quad cable - PIJF cable 88. Tapping diagram consists of _ - Distance between the tapping - Location of each tapping - Reasons for each tapping - No. of tapping 89. All new Telecom cables shall be laid close to _ - Near the telecom equipment room - Near way station - Near the railway boundary - Near the track 90. The impedance ratio of matching transformer used for VF circuits in unloaded quad cable is - 470:1120 Ohms - 470:600 Ohms - 1120:1120 Ohms - 470:470 Ohms 91. Branch off cli{> is used for _____ joint only. - Loading coil joint - Condenser joint - Normal joirit - Derivation joint 92. RDSO specification for RTSF jointing kit is. _____. - IRS-TC:77/2012 - IRS-TC:77/2011 - IRS-TC:77/2014 - IRS-TC:79/2012 93. The purpose of tinned copper braid in RTSF jointing kit is - To provide continuity between the poly al sheaths of both the cables - To provide continuity between the Aluminium screening of both the cables - For providing continuity between the conductors - To provide continuity between the GI armours of both the cables 94. The purpose of jelly in RTSF jointing kit - To provide g9od conductivity - To prevent entry of water - To avoid short circuit - For providing mechanical support 95. Induced voltages in 6 quad cable is eliminated by Earthing; - Aluminium foil - Aluminium screening wires - GI armour - Poly. Al. sheath 96. The impedance ratio of matching transformer used for block circuits in unloaded quad cable is _ - 1:2 Ohms - 470:600 Ohms - 1120: 600 Ohms - 470:1120 Ohms 97. DSLAM Stands for - Digital subscriber line access multiplexer - Data subscriber line access multiplexer - Digital subscriber line access module - Data subscriber Une access multiplexer 98. The RDSO spec for jointing kit used for PIJF telephone cables is _____ - IRS.TC.TT-2012 - IRS-TC-57/2006 - IRS.TC.77-2013 - IRS/TC/41/97 99. Purpose of sealant tape in the RTSF kit is - To wrap the conductors - To cover the metallic projections - To prevent entry of water - To seal the joint 100. Insulation resistance of quad cable shall be tested with _____ Megger after completion of jointing of cables. - 1000 V - 100 V - 250 V - 500 V 101. Transmission loss test shall be carried out with a tone frequency of _____ - 600 els - 1000 els - 400 els - 800 els 102. Cross Talk has to be measured with _____ frequency for VF Circuits - 1200 els - 1500 els - 800 els - 1000 els 103. Periodicity of conduction test carried out on a quad cable is. _____ - Weekly - Monthly - Quarterly - Yearly 104.Periodicity of insulation resistance test carried out on a quad cable is _____ - Monthly - Yearly - Quarterly - Half yearly 105.Periodicity of transmission loss test carried out on a quad cable is _____ - Quarterly - Fortnightly - Half yearly - Monthly 106. Periodicity of cross talk test carried out on a quad cable is _____ - Quarterly - Monthly - Fortnightly - Weekly 107. Periodicity of psophometric noise test carried out on a quad cable is _____ - Quarterly - Half yearly - Monthly - Yearly 108. What is the tone frequency applied for cross talk test on BPAC circuits _____ - 1000 els - 5000 els - 155 k els - 150 k els 109. Low insulation fault can be localized with the help of _____ - Digital cable fault locator - Megger - Earth tester - Multi meter 110. In digital cable fault locator, which mode is used to find out open/ short circuit fault_ - Insulation resistance - Low insulation - Foreign potential - Pulse echo reflection 111. A digital circuit that can store a bit is _____ - XOR gate - Flip flop - EX-NOR gate - Adder 112. The purpose of Integrated Cable path diagram is _ - To locate the path - For carrying out maintenance - To carry out tests - To proteg the cables 113. A binary number system has _____ many digit. - 0 - 1 - 10 - 2 114. Quad cable has to be tested periodically by JE/Tele on _____ basis - Quarterly - Weekly - Monthly - Yearly 115. Quad cable has to be tested periodically by SSE/Tele. - Weekly & monthly - Monthly & quarterly - Half yearly & yearly - Quarterly & yearly 116. Quad cable has to be inspected by Officers once in, - Monthly - Quarterly - Half yearty - Yearly 117. The insulation resistance of the 6 quad cable should be greater than ______ MOhm. - 50 - 10 - 20 - 5 118. VLRA Stands for _ - Valve-regulated lead-acid - vacuum-related lead-acid - value-regulated lead-acid - none of these 119. One of the systems that provide information at station is. _ - IVRS - CCTV - Call centre - PSTN 120. One of the System that provide information at Passenger end is - POET - Internet - CCTVs - Alpha numeric display 121. Call centre is the system providing train.n related information to the passengers - No information will be given - both at Railway station and passenger end. - at Railway station - at passenger end 122. LED based electronic Display boards are _ - Neither non interactive nor interactive - Both interactive and Non interactive - Non interactive information systems - Interactive information systems 123. Touch screen systems are also called as _ - Non interactive information systems - Indication Tenninal - Interactive information systems - Digital video recorder (DVR) is used in _ 124. Digital video recorder (DVR) is used in _ - IP based CCTV surveillance system - both In Analog based CCTV surveiUance system & IP based CCTV surveillance system - Integrated information system - Analog based CCTV surveillance system 125. Redundant Array of independent disks used in IP based CC1V Surveillance system has The storage capacity in _ - Giga bits - Kilo bits - Tera bits - Mega bits 126. In the Resistive touch screen location of the touch is determined by _ - Capacitance change - Voltage change - Frequency change - Absorption of acoustic waves 127. Digital video recorder can accommodate _____ numbers of cameras. - 16 - 8 - 64 - 32 128. In the Surface acoustic touch screen system, the location of the touch is determined by - Resistance variations - Absorption of acoustic waves - voltage changes - frequency changes 129. Keyboard are used as _ - input device - connecting device - output device - both input & output devices 130. Features such as increased availability of services, E-mail access, Fax on demand, Automatic announc!ng unit, Call back facility on reservation confirmation, Accident related queries arid Registration of complaints are available in - Call centre based IVRS - In both IVRS & Call centre based IVRS - IVRS - NTES 131. In Call centre based IVRS, connectivity between BSNL exchange and Call center is through _ - Digital circuits - Both analog and digital circuits - Analog circuits - wi-fi 132. In decimal number system what is MSD. - First digit from left to right - First digit from right to left - Middle Digit - Mean of all digit 133. The Call center fetches the dynamic data such as train arrival/departure information from. - NTES server - COIS - PRS server - both from PRS & NTES server 134. The IVRS is integrated with _ - BSNURLY exchange and PRS - Surveillance system - PRS & BSNURLY exchange - PRS & NTES data base through servers 135. When Link fails the PRS system working for ___ - 12 Hrs - 24 Hrs - Not working - 72 Hrs 136. on·one output port of MOCH, the numbers of display boards can be connected are - 4·boards - 6 boards - 8 boards - 2 boards 137. In IPIS the data speed in RS485 cable is _____. - 57.6 kbps - 4.8 kbps - 35.0 mbps - 9.6Kbps 138. The maximum length of RS232 cable used in IPIS is _____ - 15m - 1200m - 90m - 1000m 139. In IPIS, from version-3 onwards colour of the LEDs used in PDBs and CGDBs should be. _____ - Yellow - White - Red - Pl Blue 140. In version-4 of the IPIS, the following changes have been made - Number of ports are increased in hubs - IP addresses to be assigned to the devices - OFC connectivity - Blue LEDs to be used in the display boards 141. In IPIS Data speed in RS232 cable should be - 4.8 kbps - 57.6 kbps - 9.6 kbps - 100.0 kbps 142. The maximum length of the RS485 cable used in IPIS should be _____ - 1000m - 15m - 1200m - 500m 143. The serial port connection between Coach Guidance display boards along a line will be - Parallel connected - series parallel - daisy chained - serially connected 144.Data synchronization between two control consoles is through, _____ - Router - LAN switch - by cross connecting the PCs - by cross connecting the PCs or by using a LAN switch 145. The interface cable used for connecting POCH output ports to display boards is - RS232. - Coaxial cable - OFC. - RS485 146. The numbers of LED based d.isplay boards, can be connected to one 0/P port of POCH are _____ - Two boards - Six boards - Four boards - Eight boards 147.MOCH routes the incoming signals from CCU to _ - PA systems - LED based electronic display boards - Close circuit Televisions - Surveillance system 148. Platform display boards and Coach Guidance display boards in the platforms have the below said addresses. - Multicast address - Unique or Device address - Both Multicast and Device address - IP address 149. In IPIS changeover between CCUs is done by _ - Platform data communication hub - Control console unit - Main data communication hub - Eight port LAN switch 150. The oscillator in digital clocks is crystal controlled for want of _ - The more space it occupies - Poor stability of crystal oscillator - Less·space and high stability - High power consumption 151. The backup for GPS clock is from _ - Master Clock - Common reference time from GPS - Real time clock - Slave clock 152. The master-slave digital clocks obtain common reference time from the _ - Master clock only - GPS orbiting the earth - Analogue clock - Real time clock only 153. Boolean algebra A·A is equal to _____ - A - 2A - A^2 - 1 154. Boolean expression X+X·Y is. - 1 - 0 - X - Y 155. SI Unit of Force _ - Newton - watt - joule - second 156. _____ enables to extend the distance of the LAN without any loss of data in Electronic Reservation Chart system. - LAN Extender - Modem - Router - Hub 157. Charting server receives Chart data from _____ via railway network. - PRS server - Both PRS and-NTES servers - NTl:S server - COIS 158. CRT stands for _ - Cathode ray tube - carbon resistance transistor - cathode related transistor - none of1he above 159. The approximate ratio of acid to distilled water for conventional LA battery is _____. - 1:5 - 1:4 - 1:2 - 1:3 160. 1Watts equivalent to _____ dBm. - 30 - 33 - 10 - 0 161. In C/10 discharge rate, 10 indicates. _____ - Volts - Hours - Constant - 162. Unit of Capacity of a cell. _____. - Ha - Ah - A - h 163.Four no. of 4 ohm resistor connected in parallel ,what is output - 1 ohm - 16ohm - 4ohm - none of the above 164. COIS stands for _ - coach operation information system - crew operation information system - coach optical information system - coach operation integral system 165 HDBJ Stands for. - High-Density Bipolar order 3 - High-Domain Bipolar order 3 - High-Density Bipolar order terminal 3 - High-Domain Binary order 3 166. Four no. of 4F Capacitor connected in parallel ,what is output - 1F - 16 F - 4F - none of the above 167. Converter unit is for conventional of . - AC to DC only - DC to AC and DC to DC - AC to DC or DC to DC - DC to AC only 168. The max. temperature allowed during charging of LA battery shall not exceed ______ degree C. - 40 - 30 - 27 - 50 169.The codal life of re-chargeable batteries used in S&T department is. _____ - 48months - 24 months - 60 months - 36 months 170.VSAT stands for _____ - Very Small Available terminal - Very Small Aperture terminal - Very Simple Aperture terminal - Very Short Available terminal 171.Power plants which have the scope for modular expansion are _____ - Ferro-resonant - Thyristor controlled - Linear - SMPS 172. In a automatic battery charger, automatic change over from float to boost mode and vice versa will be carried out by sensing _____