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