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