ELECTRICIAN 2nd YEAR MODULE – DC Generator July 2, 2025July 2, 2025 by admin TRANSLATE THIS QUIZ IN YOUR LANGUAGE इस प्रश्नोत्तरी का अपनी भाषा में अनुवाद करें <<1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556>> 0% Question 1 of 56 1. 19. Which voltage drop is indicated in the portion marked as 'X' in a DC generator? Shunt field voltage drop Armature reaction drop Full load voltage drop Armature voltage dropQuestion 1 of 56Question 2 of 56 2. 52. How is armature reaction neutralized in large DC generators? Compensating winding Additional interpoles Increased brush contact resistance Resistance wires in windingsQuestion 2 of 56Question 3 of 56 3. 39. Why are solid pole shoes used in DC generators? Reduce copper loss Decrease residual magnetism Increase residual magnetism Reduce magnetic path reluctanceQuestion 3 of 56Question 4 of 56 4. 29. Which material is used to make brushes in generators? Cast iron and graphite Steel and graphite Aluminium and graphite Carbon and graphiteQuestion 4 of 56Question 5 of 56 5. 43. What is the purpose of the slot marked 'X' in a DC generator? Lubrication Enable air circulation Fix the keyway Easy shaft removalQuestion 5 of 56Question 6 of 56 6. 53. What happens if a DC generator is idle for a long time? Field coil resistance increases Increased armature reaction Armature resistance increases Loss of residual magnetismQuestion 6 of 56Question 7 of 56 7. 56. What causes heavy sparking in DC generator brushes? Excessive brush spring tension Shift in MNA and GNA positions Short circuit in field winding Short circuit in armature windingQuestion 7 of 56Question 8 of 56 8. 26. What is the name of the generator if its field is connected in parallel with the armature? Self-excited generator Compound generator Series generator Shunt generatorQuestion 8 of 56Question 9 of 56 9. 35. Which DC generator works without residual magnetism? Compound generator Series generator Shunt generator Separately excited generatorQuestion 9 of 56Question 10 of 56 10. 38. What is the purpose of resistance wire in commutator connections? Nullify statically induced EMF Maintain constant voltage Increase statically induced EMF Smooth current direction reversalQuestion 10 of 56Question 11 of 56 11. 33. Which DC generator is used for long-distance distribution lines? Series generator Differential compound generator Shunt generator Cumulative compound generatorQuestion 11 of 56Question 12 of 56 12. 32. Why does terminal voltage decrease with increased load in a DC shunt generator? Armature reaction effect Reduced brush voltage drop Increased armature resistance Increased shunt field inductanceQuestion 12 of 56Question 13 of 56 13. 44. What is the purpose of field coils in a DC generator? Increase magnetic path reluctance Reduce magnetizing current Magnetize poles to produce flux Increase air gap fluxQuestion 13 of 56Question 14 of 56 14. 16. How are interpoles connected in a DC generator? In parallel with the shunt field In parallel with the armature In series with the armature In series with the shunt fieldQuestion 14 of 56Question 15 of 56 15. 22. Why is the armature resistance of a DC generator kept very low? Run armature with less weight Reduce armature voltage drop Reduce armature current Reduce temperature of armatureQuestion 15 of 56Question 16 of 56 16. 13. What is the name of the part of a DC generator that provides mechanical support and a path for magnetic flux? Pole core Stator Pole shoes Yoke (or frame)Question 16 of 56Question 17 of 56 17. 34. Which method improves insulation resistance in DC generators? Regular commutator cleaning Frequent brush replacement Periodic machine heating Blowing hot air during maintenanceQuestion 17 of 56Question 18 of 56 18. 54. Calculate the induced EMF of a 4-pole, lap-wound dynamo at 1000 rpm with 600 conductors and 0.064 Wb flux/pole. 480 V 320 V 640 V 160 VQuestion 18 of 56Question 19 of 56 19. 47. Which DC generator is used for electroplating? Cumulative compound generator Series generator Differential compound generator Shunt generatorQuestion 19 of 56Question 20 of 56 20. 6. What is the name of the part marked 'X' in a DC generator (pole assembly)? Pole coil Pole shoe Pole tip Pole coreQuestion 20 of 56Question 21 of 56 21. 5. What is the formula to calculate back emf of a DC motor? BDACQuestion 21 of 56Question 22 of 56 22. 48. What is the purpose of compensating winding in DC generators? Minimize rough commutation Maintain constant output voltage Neutralize demagnetizing effect Decrease field coil excitation currentQuestion 22 of 56Question 23 of 56 23. What is the name of the DC generator described as having cumulative short shunt compounding? Differential short shunt compound Cumulative long shunt compound Differential long shunt compound Cumulative short shunt compoundQuestion 23 of 56Question 24 of 56 24. 51. Calculate the EMF generated in a 4-pole, simplex wave-wound DC generator with 1020 conductors at 1500 rpm and 0.007 Wb flux/pole. 357 V 428 V 178 V 243 VQuestion 24 of 56Question 25 of 56 25. 42. Which voltage is induced dynamically in a DC generator? Oscillating voltage Pulsating voltage Direct current voltage Alternating voltageQuestion 25 of 56Question 26 of 56 26. 9. What is the name of the DC generator's field where the series field opposes the shunt field? Differential compound generator Short shunt compound generator Cumulative compound generator Long shunt compound generatorQuestion 26 of 56Question 27 of 56 27. 55. What happens to induced EMF if main field flux distorts in a DC generator? EMF increases EMF decreases No change in EMF EMF becomes zeroQuestion 27 of 56Question 28 of 56 28. 1. What is the name of the part marked as 'X' in a DC generator? Brush Commutator segment Commutator riser Armature coreQuestion 28 of 56Question 29 of 56 29. 14. How many parallel paths are there in a duplex lap winding of a 4-pole DC generator? 8 6 12 4Question 29 of 56Question 30 of 56 30. 20. What is the name of the compound generator if the shunt field is connected in parallel with the armature? Cumulative compound Long shunt compound Short shunt compound Differential compoundQuestion 30 of 56Question 31 of 56 31. 8. Which type of energy is converted into electrical energy by a generator? Chemical energy Kinetic energy Mechanical energy Heat energyQuestion 31 of 56Question 32 of 56 32. 11. What is the formula for dynamically induced emf? BLV cosθ volts BL sinθ volts BLV sinθ volts BLV voltsQuestion 32 of 56Question 33 of 56 33. 15. Name the part of a DC generator that consists of thin laminated sheets to reduce eddy currents. Side end plates Pole shoe lamination Commutator segment Armature core laminationQuestion 33 of 56Question 34 of 56 34. 10. What is the principle of a DC generator? Cork screw rule Fleming’s left hand rule Fleming’s right hand rule Faraday’s laws of electromagnetic inductionQuestion 34 of 56Question 35 of 56 35. 21. Why is the armature core of a DC generator laminated? Reduce friction loss Reduce hysteresis loss Reduce copper loss Reduce eddy current lossQuestion 35 of 56Question 36 of 56 36. 37. What is the property of wave winding in DC generators? High current, high voltage Low current, low voltage High current, low voltage Low current, high voltageQuestion 36 of 56Question 37 of 56 37. 36. Which DC generator is used for arc welding? Shunt generator Differential compound generator Cumulative compound generator Series generatorQuestion 37 of 56Question 38 of 56 38. 3. Which rule is used to find the direction of induced emf in a DC generator? Right hand palm rule Fleming's left hand rule Fleming's right hand rule Cork screw ruleQuestion 38 of 56Question 39 of 56 39. 24. Why is compensating winding provided in large DC generators? Reduce commutation effect Increase generator efficiency Neutralize armature reaction effect Connect more loadsQuestion 39 of 56Question 40 of 56 40. 31. How does the magnetic circuit complete through the yoke and poles in a generator? Field coils Armature core Laminated pole core Armature winding conductorsQuestion 40 of 56Question 41 of 56 41. 27. What is the purpose of pole shoes in a DC generator? Minimize magnetic losses Reduce air gap Increase field strength Spread flux uniformly in the air gapQuestion 41 of 56Question 42 of 56 42. 23. Why should a DC generator run only in the clockwise direction? Protect brushes from damage Avoid short circuit in armature Protect residual magnetism Avoid generator overloadingQuestion 42 of 56Question 43 of 56 43. 7. What is the name of the DC generator that requires separate excitation? Separately excited generator Compound generator Shunt generator Series generatorQuestion 43 of 56Question 44 of 56 44. 17. What is the necessity of residual magnetism in a self-excited DC generator? To maintain constant output voltage To reduce the field current To build up the voltage To reduce armature currentQuestion 44 of 56Question 45 of 56 45. 28. What is the function of split rings in a DC generator? Reduce voltage drop at brushes Increase terminal voltage beyond rated Maintain constant voltage Collect current unidirectionallyQuestion 45 of 56Question 46 of 56 46. 46. Why are pole core stampings laminated in DC generators? Reduce hysteresis loss Reduce windage loss Reduce eddy current loss Reduce friction lossQuestion 46 of 56Question 47 of 56 47. 49. What happens if shunt field resistance exceeds critical value in a DC generator? Above-normal output voltage Pulsating output voltage Voltage buildup failure Normal voltage buildupQuestion 47 of 56Question 48 of 56 48. 4. Which formula is used to calculate the generated emf in a DC generator? ADCBQuestion 48 of 56Question 49 of 56 49. 40. Which metal is used for large-capacity DC generator yokes? Soft iron Rolled steel Cast iron AluminiumQuestion 49 of 56Question 50 of 56 50. 18. Which two points measure the brush contact resistance in DC machines? Resistance between brush and commutator Resistance between the opposite brushes Resistance between brush and commutator riser Resistance between brush and armature conductorsQuestion 50 of 56Question 51 of 56 51. 45. Which metal is used for pole cores in large DC generators? Cast iron Stainless steel Cast steel Soft ironQuestion 51 of 56Question 52 of 56 52. 30. Why do DC generators lose residual magnetism? Heavy short circuit in load Uninterrupted operation Frequent direction changes of rotation Continuous no-load runningQuestion 52 of 56Question 53 of 56 53. 12. Which rule is used to find the direction of a magnetic field? Right hand palm rule Fleming’s right hand rule Cork screw rule Fleming’s left hand ruleQuestion 53 of 56Question 54 of 56 54. 50. What is the effect of armature reaction in DC generators? Decreased output voltage Pulsating output voltage Zero output voltage Increased output voltageQuestion 54 of 56Question 55 of 56 55. 41. What is the function of split rings in a DC generator? Unidirectional output Collect output from alternate conductors Opposite direction output Continuous output supplyQuestion 55 of 56Question 56 of 56 56. 25. What is the reason a DC generator fails to build up voltage? Prime mover running above rated speed Loose brush contact Field resistance above critical value High armature resistanceQuestion 56 of 56 Loading...
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