ELECTRICIAN 2nd YEAR MODULE – DC Motor MCQ July 2, 2025July 2, 2025 by admin TRANSLATE THIS QUIZ IN YOUR LANGUAGE इस प्रश्नोत्तरी का अपनी भाषा में अनुवाद करें <<1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768>> 0% Question 1 of 68 1. 63. Why the newly rewound armature must be preheated before varnishing? Drive out the moisture from it Make easy to penetrate varnish inside Maintain uniform spreading of varnishing Help for quick drying of varnishQuestion 1 of 68Question 2 of 68 2. 2. Which instrument is used to test armature winding for short and open circuit? External Growler Internal Growler Digital multimeter Tong TesterQuestion 2 of 68Question 3 of 68 3. 16. What is the purpose of series resistor connected with holding coil in a D.C four point starter? Limit the current in holding coil Increase the voltage in holding coil Decrease the voltage in holding coil Increase the current in holding coilQuestion 3 of 68Question 4 of 68 4. 62. Which type of test is illustrated for the armature after rewound? Shorted coil test Open coil test Voltage drop test Grounded coil testQuestion 4 of 68Question 5 of 68 5. 49. What is the best method to change the DOR of a compound motor without change of its characteristics? Change the current in armature and shunt field together Change shunt field current direction Change armature current direction Change series field current directionQuestion 5 of 68Question 6 of 68 6. 1. Which instrument is used to measure armature winding resistance? Multimeter Megger Series type Ohm meter Kelvin bridgeQuestion 6 of 68Question 7 of 68 7. 53. Which speed control system provides a smooth variation of speed from zero to above normal? Field control Ward-Leonard system control Field diverter control Armature controlQuestion 7 of 68Question 8 of 68 8. 25. Which type of DC motor is used in elevators? DC cumulative compound motor DC series motor DC shunt motor DC differential compound motorQuestion 8 of 68Question 9 of 68 9. 55. Which type of DC armature winding the front pitch (YF) is greater than back pitch (YB)? Retrogressive winding Progressive winding Wave winding Lap windingQuestion 9 of 68Question 10 of 68 10. 59. Which insulating material used in winding is a highly non-hygroscopic and possess good electrical strength? Leatheroid paper Empire cloth Triplex paper Millinex paperQuestion 10 of 68Question 11 of 68 11. 40. Which motor has this characteristics curve? Series motor Shunt motor Differential compound motor Cumulative compound motorQuestion 11 of 68Question 12 of 68 12. 15. What is the name of winding, if coil pitch is less than pole pitch? Short chorded winding Half pitch winding Long chorded winding Full pitch windingQuestion 12 of 68Question 13 of 68 13. 35. Which type of armature winding is illustrated? Triplex lap winding Simplex lap winding Quadruplex lap winding Duplex lap windingQuestion 13 of 68Question 14 of 68 14. 51. Which type of DC motor is used for sudden application of heavy loads? Shunt motor Differential compound motor Series motor Cumulative compound motorQuestion 14 of 68Question 15 of 68 15. 57. How to obtain opposite polarity in adjacent poles of a 4 pole DC motor? Making series connection of coils Making parallel connection of coils Varying the number of turns in coil Making current flow in different directionQuestion 15 of 68Question 16 of 68 16. 26. Which method of speed control gives below the rated speed in DC series motor? Field diverter method Voltage control method Tapped field method Armature diverter methodQuestion 16 of 68Question 17 of 68 17. 4. Which winding wire is used for DC field coil? Single silk covered copper wire PVC covered copper winding wire Super enameled copper wire Double silk covered copper wireQuestion 17 of 68Question 18 of 68 18. 67. What is the reason for reduction in speed of a D.C shunt motor from no load to full load? Armature voltage drop increases Armature voltage drop decreases Shunt field current increases Shunt field current decreasesQuestion 18 of 68Question 19 of 68 19. 38. Why commutators are sparking heavily? Incorrect direction of rotation Incorrect brush position Incorrect field connection Incorrect armature connectionQuestion 19 of 68Question 20 of 68 20. 21. Why starters are required to start D.C motors in industries? Control the armature reaction Regulate the field voltage Reduce the armature current Smooth operation of motorsQuestion 20 of 68Question 21 of 68 21. 22. Which insulating material belongs to class 'B' insulation? Fiber glass Cotton Bamboo Leatheroid paperQuestion 21 of 68Question 22 of 68 22. 45. Where D.C compound motors are preferred? Constant speed requirements High starting torque requirements Constant speed under varying load requirements Constant load requirementsQuestion 22 of 68Question 23 of 68 23. 37. Which speed control method is applied to obtain both below normal and above normal speed in DC motor? Ward Leonard speed control Tapped field speed control Armature control method Field control methodQuestion 23 of 68Question 24 of 68 24. 11. Which rule is applied to identify the direction of flux in DC motor? Fleming's left hand rule Fleming's right hand rule Right hand grip rule Cork's screw ruleQuestion 24 of 68Question 25 of 68 25. 44. Which type of D.C motor is suitable for shearing machines? Differential compound motor Series motor Cumulative compound motor Shunt motorQuestion 25 of 68Question 26 of 68 26. 20. Which speed control methods offers below normal speed in DC shunt motor? Voltage control method Ward Leonard system of speed control Field control method Armature control methodQuestion 26 of 68Question 27 of 68 27. 6. How many parallel paths in duplex lap winding in the armature of 4 pole D.C Motor? 8 6 2 4Question 27 of 68Question 28 of 68 28. 61. Calculate the average pitch (YA ) for retrogressive wave winding, if No. of armature conductor = 14, No. of slots = 7, No. of poles = 2 14 6 4 8Question 28 of 68Question 29 of 68 29. 12. Name the type of DC motor. Short shunt compound motor Long shunt compound motor Series motor Shunt motorQuestion 29 of 68Question 30 of 68 30. 39. What is the action of the induced emf in a running D.C motor? Assists the applied voltage Decreases the armature current Increases the armature current Opposes the applied voltageQuestion 30 of 68Question 31 of 68 31. 24. Which type of D.C motor is used for constant speed drives? Differential short shunt compound motor DC shunt motor Differential long shunt compound motor DC series motorQuestion 31 of 68Question 32 of 68 32. 66. What is the speed, if field winding of a DC shunt motor is in open circuit? Runs at slow speed Runs in very high speed Motor runs normally Stop runningQuestion 32 of 68Question 33 of 68 33. 33. Which DC compound motor is operated at constant speed under varying load? Cumulative long shunt Differential long shunt Cumulative short shunt Differential short shuntQuestion 33 of 68Question 34 of 68 34. 43. Which type of speed control of D.C series motor? Field parallel method Field tapping method Field diverter method Armature diverter methodQuestion 34 of 68Question 35 of 68 35. 41. What is the purpose of resistor connected with holding coil in 4 point starter? Limit current in NVC Protect the motor from overload Protect the coil from short circuit Protect the armature from short circuitQuestion 35 of 68Question 36 of 68 36. 48. Why the holding coil of a 3 point starter is connected in series with shunt field? To hold the handle plunger firmly To run motor at low voltage To protect the motor from high speed To limit the load currentQuestion 36 of 68Question 37 of 68 37. 56. What reduces the cross sectional area of core material for VA rating? Dynamo sheet Low alloy sheet High alloy sheet Normal steel sheetQuestion 37 of 68Question 38 of 68 38. 46. What is the necessity of starter for D.C motor? Limit the field voltage Limit the field current Limit the armature current Control the motor speedQuestion 38 of 68Question 39 of 68 39. 58. What is the operation in the rewinding process? Removing of winding Cleaning of slots Removing of wedges Cutting of winding wireQuestion 39 of 68Question 40 of 68 40. 29. Why series motor produce high torque and speed initially without load? Load current flows through field winding Series field winding wound with thick wire Armature current and field current are same Absence of back emfQuestion 40 of 68Question 41 of 68 41. 17. Which speed control method of D.C series motor is used for electric train? Field diverter method Field tapping method Armature diverter method Supply voltage control methodQuestion 41 of 68Question 42 of 68 42. 14. What is the name of the equipment? Megger External growler Internal growler Earth resistance testerQuestion 42 of 68Question 43 of 68 43. 5. Which formula is used to calculate the speed of DC motor?Question 43 of 68Question 44 of 68 44. 28. Why carbon composition brush requires in the armature circuit to operate the D.C motor? Increases the starting torque Protects from armature reaction Reduces the spark in the commutator segment Protects armature from over loadingQuestion 44 of 68Question 45 of 68 45. 65. What is the effect in a D.C shunt motor, if its supply terminals are interchanged? Runs in slow speed Runs in high speed Runs in the same direction Runs in the reverse directionQuestion 45 of 68Question 46 of 68 46. 50. What is the purpose of NVC connected in series with the field in 3 point starter? To improve the torque To decrease the back emf To prevent increase in speed Reduce the field currentQuestion 46 of 68Question 47 of 68 47. 23. What is the temperature value of class 'F' insulation? 90°C 155°C 120°C 105°CQuestion 47 of 68Question 48 of 68 48. 54. What is the purpose of tapes in winding? Insulate slots Bind the coils Insulate exposed conductors Wrap the conductorQuestion 48 of 68Question 49 of 68 49. 34. How No volt coil is connected in a three point starter with DC shunt motor? Directly connected to supply Connected in series with shunt field Connected in series with armature Connected in parallel with armatureQuestion 49 of 68Question 50 of 68 50. 8. What is the name of D.C motor? D.C series motor D.C cumulative compound motor D.C differential compound motor D.C shunt motorQuestion 50 of 68Question 51 of 68 51. 10. What is the formula to calculate the current taken by D.C shunt motor armature?Question 51 of 68Question 52 of 68 52. 36. Which growler test for armature is illustrated? Shorted commutator test Grounded coil test Open coil test Shorted coil testQuestion 52 of 68Question 53 of 68 53. 9. Which rule determines the direction of current in D.C motor? Fleming's left hand rule Right hand palm rule Right hand grip rule Fleming's right hand ruleQuestion 53 of 68Question 54 of 68 54. 19. Why the direction of rotation is changed only by changing the armature current direction in a D.C compound motor? Maintain rated speed Maintain motor characteristics Avoid armature reaction effect Prevent motor from over loadingQuestion 54 of 68Question 55 of 68 55. 47. Which type of instrument is used to test the armature winding? Megger Growler Multimeter OhmmeterQuestion 55 of 68Question 56 of 68 56. 32. Which material is used for starting resistance of DC starters? Manganin Constantine Nichrome EurekaQuestion 56 of 68Question 57 of 68 57. 3. What is the name of the speed control method of DC motor? Field tapping method Field diverter method Armature diverter method Voltage control methodQuestion 57 of 68Question 58 of 68 58. 27. What is the effect, if a four point starter resistance is cutoff during running? Runs at reverse direction Motor stopped Runs at slow speed Runs at very high speedQuestion 58 of 68Question 59 of 68 59. 18. Why shunt field coil is connected in series with holding coil in D.C three point starter? Increase the holding coil current Protect the shunt field from over current Decrease the holding coil current Protect the motor in case of open in shunt fieldQuestion 59 of 68Question 60 of 68 60. 31. Which is the most effective method of balancing armature? Static balancing Attached with counter balancing Plugged with lead weight balancing Dynamic balancingQuestion 60 of 68Question 61 of 68 61. 30. Why the series field is short circuited at the time of starting in differential compound motor? To increase the speed of motor To decrease the speed of motor To reduce the starting current To maintain proper direction of rotationQuestion 61 of 68Question 62 of 68 62. 52. Which speed control method is used in food mixture motors? Armature diverter method Field diverter control method Voltage control method Series field tapping methodQuestion 62 of 68Question 63 of 68 63. 64. How the direction of rotation of a DC compound motor is changed? By changing the direction of armature current By changing the direction of both field and armature current By changing the direction of series field current By interchanging the supply terminalsQuestion 63 of 68Question 64 of 68 64. 68. Which winding fault is determined by the test? Open coil fault Short coil fault Grounded core fault Grounded coil faultQuestion 64 of 68Question 65 of 68 65. 60. Which type of armature winding is illustrated? Retrogressive lap winding Duplex wave winding Progressive lap winding Triplex wave windingQuestion 65 of 68Question 66 of 68 66. 13. What is the formula to calculate back EMF in a DC motor?Question 66 of 68Question 67 of 68 67. 7. Which rule determines the direction of rotation of armature in D.C motor? Fleming's right hand rule Right hand grip rule Right hand palm rule Fleming's left hand ruleQuestion 67 of 68Question 68 of 68 68. 42. Why the D.C series motor field winding is wound with thick wire? To reduce the armature reaction To carry the load current To keep maximum inductance To regulate field voltageQuestion 68 of 68 Loading...
