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