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