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