Railways NTPC (Technical Ability) Utlization of Electrical Energy Question Bank

done Utlization of Electrical Energy Total Questions - 50

• question_answer1)
  Method which is appropriate for heating non-ferrous metals?
  A)
    Dielectric heating done clear
  B)
   Radiant heating done clear
  C)
    Indirect arc heating done clear
  D)
   Indirect resistance heating done clear
  View Solution play_arrow

• question_answer2)
  Methods which is suitable for the heating of conducting medium is
  A)
   Radiant heating done clear
  B)
   Eddy current heating done clear
  C)
   Induction heating      done clear
  D)
   Indirect arc heating done clear
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• question_answer3)
  Which of the following comparisons between the filament lamp and the fluorescent lamp is correct?
  A)
   The fluorescent lamp has a higher dazzle done clear
  B)
   The fluorescent lamp produces sharper shadows done clear
  C)
   The fluorescent lamp produces greater brightness done clear
  D)
   The average life of the fluorescent lamp is five to seven times higher done clear
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• question_answer4)
  Which of the following statements about illumination is true?
  A)
   If the distance from the source doubles, the illumination becomes half done clear
  B)
   If the distance from the source doubles, the illumination reduces to one fourth done clear
  C)
   The greater the illumination, the better one sees done clear
  D)
   The finer the work, the less the required illumination done clear
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• question_answer5)
  High frequency for induction heating can be generated by
  A)
   motor generator set done clear
  B)
   spark gap oscillator done clear
  C)
   vacuum tube oscillator done clear
  D)
   all of these done clear
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• question_answer6)
  Flux used in TIG welding is
  A)
   Ammonium chloride       done clear
  B)
   Borax done clear
  C)
   Ash                              done clear
  D)
   None of these done clear
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• question_answer7)
  In Argon are welding, the electrode is made of
  A)
   carbon              done clear
  B)
   steel done clear
  C)
   tungsten                        done clear
  D)
   no electrode is needed done clear
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• question_answer8)
  A 10-SWG electrode has approximate diameter of
  A)
   0.9 mm                        done clear
  B)
   1.2 mm done clear
  C)
   3.3 mm                        done clear
  D)
   10 mm done clear
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• question_answer9)
  In gas welding, the gases used are
  A)
   oxygen and nitrogen done clear
  B)
   argon and helium done clear
  C)
   helium and carbon dioxide done clear
  D)
   acetylene and oxygen done clear
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• question_answer10)
  Grey iron is usually welded by
  A)
   Arc welding                   done clear
  B)
   Gas welding done clear
  C)
   TIG welding                  done clear
  D)
   MIG welding done clear
  View Solution play_arrow

• question_answer11)
  The danger of electric shock is maximum
  A)
   during arcing done clear
  B)
   after arcing done clear
  C)
   before welding done clear
  D)
   while inserting electrode into the holder done clear
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• question_answer12)
  The transformer used for a. c. welding sets is
  A)
   Booster type                  done clear
  B)
   Step-up transformer done clear
  C)
   Step-down transformer    done clear
  D)
   None of these done clear
  View Solution play_arrow

• question_answer13)
  A welding accessory is
  A)
   Electrode holder done clear
  B)
   Hand screen done clear
  C)
   Gloves              done clear
  D)
   All of these done clear
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• question_answer14)
  For regenerative braking, the regenerated power should have
  A)
   the same frequency as that of the main supply done clear
  B)
   frequency 173 of that of the main supply done clear
  C)
   frequency 1/2 of that of the main supply done clear
  D)
   any frequency done clear
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• question_answer15)
  Bearings used to support axles of rolling stock are
  A)
   bush bearings    done clear
  B)
   journal bearings done clear
  C)
   ball bearings                  done clear
  D)
   roller bearings done clear
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• question_answer16)
  D.C. supply can be obtained from A. C. supply by the use of
  A)
   motor generator set        done clear
  B)
   mercury arc rectifier done clear
  C)
   silicon diodes                 done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer17)
  Ward-Leonard controlled d.c. drives are generally used for
  A)
   light duty excavators done clear
  B)
   medium duty excavators done clear
  C)
   heavy duty excavators done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer18)
  Motor used for elevators is generally
  A)
   synchronous motor done clear
  B)
   induction motor done clear
  C)
   capacitor start single-phase induction motor done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer19)
  Earth Least preferred for earthling is
  A)
    earth mixed with salt and charcoal done clear
  B)
   dry earth done clear
  C)
   mashy ground containing brine waste done clear
  D)
   clay soil done clear
  View Solution play_arrow

• question_answer20)
  Miniature lamps on automobiles are used for
  A)
   tail                               done clear
  B)
   dash board lamp done clear
  C)
   side lamp                      done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer21)
  The heating time constant of a totally enclosed motor is relatively
  A)
    higher done clear
  B)
   lower done clear
  C)
   independent of type of enclosure done clear
  D)
   none of these done clear
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• question_answer22)
  Wound rotor and squirrel-cage motors with high slip which develop maximum torque at stand still are used for
  A)
   presses and punches       done clear
  B)
   machine tools done clear
  C)
   elevators                       done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer23)
  Premature blowing of a fuse may occur due to
  A)
   heating at ferrule contacts done clear
  B)
   corrosion or oxidation of ferrules done clear
  C)
   weak contact pressure done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer24)
  The earth wise should not be thinner than a
  A)
   18 SWG wire                 done clear
  B)
   16SWG wire done clear
  C)
   10SWG wire                  done clear
  D)
   SSWG wire done clear
  View Solution play_arrow

• question_answer25)
  1 Mixture preferred for filling around the earth for electrode effective earthing is
  A)
   bone-meat mixture         done clear
  B)
   coal-salt mixture done clear
  C)
   saw-dust sand mixture    done clear
  D)
   lime-sand mixture done clear
  View Solution play_arrow

• question_answer26)
  Motor used for elevators is generally
  A)
   synchronous motor done clear
  B)
   induction motor done clear
  C)
   capacitor star single-phase induction motor done clear
  D)
   any of these done clear
  View Solution play_arrow

• question_answer27)
  A locomotive exerts a tractive effort of 40,000 N in pulling a rain at 60 kmph on a level track. If the same train is to be mauled at the same speed but on gradient, the tractive effort required will be 60,000 N. The output delivered by the motor will be more if it is driven by
  A)
   a 3 -phase induction motor done clear
  B)
   a dc series motor done clear
  C)
   an ac series motor done clear
  D)
   equal in all the three cases done clear
  View Solution play_arrow

• question_answer28)
  Wound rotor and squirrel-cage motors with high slip which develop maximum torque at stand still are used for
  A)
   presses and punches       done clear
  B)
   machine tools done clear
  C)
   elevators                       done clear
  D)
   all of these done clear
  View Solution play_arrow

• question_answer29)
  The basic elements of an electric drive are
  A)
   electric motor and the transmission system done clear
  B)
   electric motor, the transmission and control system done clear
  C)
   the transmission and control system done clear
  D)
   electric motor and conversion equipment?s done clear
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• question_answer30)
  The amount of energy returned to the line during regeneration depends on
  A)
   the initial and final speeds during regenerative braking done clear
  B)
   efficiency of the system done clear
  C)
   the train resistance and gradient of track also in case the train is moving down the gradient done clear
  D)
   all of the above done clear
  View Solution play_arrow

• question_answer31)
  The device necessarily used for automatic temperature control in a furnace is
  A)
   thermostat                    done clear
  B)
   auto-transformer done clear
  C)
   thermo-couple   done clear
  D)
   any of the above done clear
  View Solution play_arrow

• question_answer32)
  A single phase reluctance motor
  A)
   has salient pole rotor structure and runs at sub synchronous speed done clear
  B)
   has salient pole rotor structure and runs at super-synchronous speed done clear
  C)
   has salient pole rotor structure and runs at synchronous speed done clear
  D)
   has not-salient pole rotor structure and runs at synchronous speed done clear
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• question_answer33)
  For 600 V d. c. line for tram cars
  A)
   track is connected to negative of the supply done clear
  B)
   track is connected to positive of the supply done clear
  C)
   track is connected to mid voltage of 300 V done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer34)
  Utilisation factor depends upon
  A)
   size of the room done clear
  B)
   space height ratio of the lamps done clear
  C)
    colour of walls/ceiling done clear
  D)
   all of the above done clear
  View Solution play_arrow

• question_answer35)
  Which of the following site will be preferred for earthing?
  A)
   Wet mashy ground done clear
  B)
   Clay soil done clear
  C)
   Loam mixed with small quantities of sand done clear
  D)
   Damp and wet sand pit done clear
  View Solution play_arrow

• question_answer36)
  Which of the following heating elements can give highest temperature in resistance heating?
  A)
   Copper             done clear
  B)
   Nickel copper done clear
  C)
   Nichrome                      done clear
  D)
   Silicon carbide done clear
  View Solution play_arrow

• question_answer37)
  The power factor at which the direct arc furnace operates is
  A)
   low lagging                    done clear
  B)
   low leading done clear
  C)
   unity                            done clear
  D)
   high leading done clear
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• question_answer38)
  In Kando system of track electrification
  A)
    single phase a. c. is converted into d. c. done clear
  B)
   single phase a. c. is converted into 3-phase a.c. done clear
  C)
    3 phase a. c. is converted into d.c. done clear
  D)
   3 phase a. c. is converted into single phase a. c. done clear
  View Solution play_arrow

• question_answer39)
  Belied slip ring induction motor is almost invariably used for
  A)
   centrifugal blowers          done clear
  B)
   water pumps done clear
  C)
   jaw crushers                  done clear
  D)
   heavy load done clear
  View Solution play_arrow

• question_answer40)
  Inside the earth or pit, the earthing electrode should be placed
  A)
   vertical             done clear
  B)
   horizontal done clear
  C)
    inclined at \[45{}^\circ \]          done clear
  D)
   none of these done clear
  View Solution play_arrow

• question_answer41)
  Which of the following statements about illumination is true?
  A)
   if the distance from me source doubles, the illumination becomes half done clear
  B)
   if the distance from the source doubles, the illumination reduces to one fourth done clear
  C)
   The greater the illumination, the better on sees done clear
  D)
   The finer the work, the less the required illumination done clear
  View Solution play_arrow

• question_answer42)
  Which of the following devices is necessarily required for automatic temperature control in a furnace?
  A)
   Thermocouple done clear
  B)
   Thermostat done clear
  C)
   Auto-transformer done clear
  D)
   Heating elements of variable resistance material done clear
  View Solution play_arrow

• question_answer43)
  Nichrome wires can be safely used for heating to temperature around\[1500{}^\circ C\].Which of the following materials for heating elements should be selectd?
  A)
   Eureka done clear
  B)
   Kanthal done clear
  C)
   Platimum moly benum, carbon compound done clear
  D)
   Nichrome done clear
  View Solution play_arrow

• question_answer44)
  The dc series motor is most suitable for tranction services but more particularly for urban/suburban services because
  A)
   dc series motors are suitable for regenerative braking done clear
  B)
   dc series motors are capable of withstanding rapid fluctuations in supply voltage done clear
  C)
   dc series motors are capable of developing high torque at start done clear
  D)
   de series motors are capable of withstanding temporary interruption of supply without undue rush of current done clear
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• question_answer45)
  In a domestic baking oven, the temperature is controlled by
  A)
    voltage done clear
  B)
    series-parallel operation done clear
  C)
   thermostate done clear
  D)
   star-delta connections done clear
  View Solution play_arrow

• question_answer46)
  The diameter of a \[50-SWG\]wire is closer to           
  A)
   0.0253 mm                   done clear
  B)
   0.05 mm             done clear
  C)
   0.16 mm                      done clear
  D)
   0.52 mm         done clear
  View Solution play_arrow

• question_answer47)
  Applied voltage across the motor terminals during starting is not reduced in case of
  A)
    Star-delta starting                               done clear
  B)
   Rotor-resistance starting                       done clear
  C)
   Auto-trans former starting                     done clear
  D)
   Stator resistance starting                done clear
  View Solution play_arrow

• question_answer48)
  The electric locomotives run faster at curved routes compared to steam locomotives as:                   
  A)
   the centre of gravity of electric locomotive is higher than that of steam locomotive               done clear
  B)
   the centre of gravity of electric locomotive is lo than that of steam locomotive                 done clear
  C)
   the speed at curved routes is independent of location of centre of gravity                         done clear
  D)
   none of these       done clear
  View Solution play_arrow

• question_answer49)
                         The illumination level required for precision work is about
  A)
    \[500-1000\,\,lux\]         done clear
  B)
   250 hux            done clear
  C)
    100 lux                        done clear
  D)
   50 lux            done clear
  View Solution play_arrow

• question_answer50)
  Electric traction in comparison to other traction systems has the advantage(s) of                           
  A)
   higher acceleration and braking retardation      done clear
  B)
   cleanest system and so ideally suitable for underground and tube railways               done clear
  C)
   letter speed control                          done clear
  D)
   all of the above       done clear
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