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