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