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