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 parallel with the shunt field In series with the shunt field In series with the armatureQuestion 1 of 56Question 2 of 56 2. 25. What is the reason a DC generator fails to build up voltage? Prime mover running above rated speed Loose brush contact High armature resistance Field resistance above critical valueQuestion 2 of 56Question 3 of 56 3. 46. Why are pole core stampings laminated in DC generators? Reduce hysteresis loss Reduce windage loss Reduce eddy current loss Reduce friction lossQuestion 3 of 56Question 4 of 56 4. 19. Which voltage drop is indicated in the portion marked as 'X' in a DC generator? Armature reaction drop Full load voltage drop Armature voltage drop Shunt field voltage dropQuestion 4 of 56Question 5 of 56 5. 39. Why are solid pole shoes used in DC generators? Decrease residual magnetism Reduce magnetic path reluctance Increase residual magnetism Reduce copper lossQuestion 5 of 56Question 6 of 56 6. 38. What is the purpose of resistance wire in commutator connections? Smooth current direction reversal Nullify statically induced EMF Maintain constant voltage Increase statically induced EMFQuestion 6 of 56Question 7 of 56 7. 28. What is the function of split rings in a DC generator? Maintain constant voltage Reduce voltage drop at brushes Increase terminal voltage beyond rated Collect current unidirectionallyQuestion 7 of 56Question 8 of 56 8. 40. Which metal is used for large-capacity DC generator yokes? Soft iron Rolled steel Aluminium Cast ironQuestion 8 of 56Question 9 of 56 9. 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 9 of 56Question 10 of 56 10. 24. Why is compensating winding provided in large DC generators? Reduce commutation effect Increase generator efficiency Connect more loads Neutralize armature reaction effectQuestion 10 of 56Question 11 of 56 11. 8. Which type of energy is converted into electrical energy by a generator? Mechanical energy Chemical energy Heat energy Kinetic energyQuestion 11 of 56Question 12 of 56 12. 54. Calculate the induced EMF of a 4-pole, lap-wound dynamo at 1000 rpm with 600 conductors and 0.064 Wb flux/pole. 160 V 640 V 480 V 320 VQuestion 12 of 56Question 13 of 56 13. 21. Why is the armature core of a DC generator laminated? Reduce hysteresis loss Reduce copper loss Reduce friction loss Reduce eddy current lossQuestion 13 of 56Question 14 of 56 14. 27. What is the purpose of pole shoes in a DC generator? Reduce air gap Minimize magnetic losses Spread flux uniformly in the air gap Increase field strengthQuestion 14 of 56Question 15 of 56 15. 34. Which method improves insulation resistance in DC generators? Frequent brush replacement Blowing hot air during maintenance Periodic machine heating Regular commutator cleaningQuestion 15 of 56Question 16 of 56 16. 41. What is the function of split rings in a DC generator? Unidirectional output Continuous output supply Collect output from alternate conductors Opposite direction outputQuestion 16 of 56Question 17 of 56 17. 22. Why is the armature resistance of a DC generator kept very low? Reduce temperature of armature Run armature with less weight Reduce armature current Reduce armature voltage dropQuestion 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 Short shunt compound generator Long shunt compound generatorQuestion 18 of 56Question 19 of 56 19. 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 Short shunt compound Cumulative compoundQuestion 19 of 56Question 20 of 56 20. 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 20 of 56Question 21 of 56 21. 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 21 of 56Question 22 of 56 22. 36. Which DC generator is used for arc welding? Shunt generator Cumulative compound generator Series generator Differential compound generatorQuestion 22 of 56Question 23 of 56 23. 30. Why do DC generators lose residual magnetism? Frequent direction changes of rotation Uninterrupted operation Heavy short circuit in load Continuous no-load runningQuestion 23 of 56Question 24 of 56 24. 47. Which DC generator is used for electroplating? Differential compound generator Series generator Cumulative compound generator Shunt generatorQuestion 24 of 56Question 25 of 56 25. 35. Which DC generator works without residual magnetism? Series generator Shunt generator Separately excited generator Compound generatorQuestion 25 of 56Question 26 of 56 26. 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. 428 V 357 V 178 V 243 VQuestion 26 of 56Question 27 of 56 27. 5. What is the formula to calculate back emf of a DC motor? ABDCQuestion 27 of 56Question 28 of 56 28. 37. What is the property of wave winding in DC generators? Low current, high voltage High current, low voltage High current, high voltage Low current, low voltageQuestion 28 of 56Question 29 of 56 29. 6. What is the name of the part marked 'X' in a DC generator (pole assembly)? Pole coil Pole shoe Pole core Pole tipQuestion 29 of 56Question 30 of 56 30. 52. How is armature reaction neutralized in large DC generators? Additional interpoles Increased brush contact resistance Compensating winding Resistance wires in windingsQuestion 30 of 56Question 31 of 56 31. 14. How many parallel paths are there in a duplex lap winding of a 4-pole DC generator? 4 6 12 8Question 31 of 56Question 32 of 56 32. 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 32 of 56Question 33 of 56 33. 33. Which DC generator is used for long-distance distribution lines? Differential compound generator Shunt generator Series generator Cumulative compound generatorQuestion 33 of 56Question 34 of 56 34. 23. Why should a DC generator run only in the clockwise direction? Avoid generator overloading Protect brushes from damage Protect residual magnetism Avoid short circuit in armatureQuestion 34 of 56Question 35 of 56 35. 31. How does the magnetic circuit complete through the yoke and poles in a generator? Laminated pole core Field coils Armature winding conductors Armature coreQuestion 35 of 56Question 36 of 56 36. 45. Which metal is used for pole cores in large DC generators? Stainless steel Soft iron Cast iron Cast steelQuestion 36 of 56Question 37 of 56 37. 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 reduce armature current To maintain constant output voltageQuestion 37 of 56Question 38 of 56 38. 49. What happens if shunt field resistance exceeds critical value in a DC generator? Pulsating output voltage Voltage buildup failure Normal voltage buildup Above-normal output voltageQuestion 38 of 56Question 39 of 56 39. 44. What is the purpose of field coils in a DC generator? Increase magnetic path reluctance Magnetize poles to produce flux Increase air gap flux Reduce magnetizing currentQuestion 39 of 56Question 40 of 56 40. 26. What is the name of the generator if its field is connected in parallel with the armature? Shunt generator Self-excited generator Compound generator Series generatorQuestion 40 of 56Question 41 of 56 41. 29. Which material is used to make brushes in generators? Cast iron and graphite Steel and graphite Aluminium and graphite Carbon and graphiteQuestion 41 of 56Question 42 of 56 42. 10. What is the principle of a DC generator? Faraday’s laws of electromagnetic induction Cork screw rule Fleming’s right hand rule Fleming’s left hand ruleQuestion 42 of 56Question 43 of 56 43. 48. What is the purpose of compensating winding in DC generators? Decrease field coil excitation current Neutralize demagnetizing effect Minimize rough commutation Maintain constant output voltageQuestion 43 of 56Question 44 of 56 44. 50. What is the effect of armature reaction in DC generators? Increased output voltage Pulsating output voltage Decreased output voltage Zero output voltageQuestion 44 of 56Question 45 of 56 45. 4. Which formula is used to calculate the generated emf in a DC generator? CABDQuestion 45 of 56Question 46 of 56 46. 11. What is the formula for dynamically induced emf? BL sinθ volts BLV sinθ volts BLV cosθ volts BLV voltsQuestion 46 of 56Question 47 of 56 47. What is the name of the DC generator described as having cumulative short shunt compounding? Differential short shunt compound Cumulative long shunt compound Differential long shunt compound Cumulative short shunt compoundQuestion 47 of 56Question 48 of 56 48. 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 48 of 56Question 49 of 56 49. 43. What is the purpose of the slot marked 'X' in a DC generator? Lubrication Fix the keyway Enable air circulation Easy shaft removalQuestion 49 of 56Question 50 of 56 50. 7. What is the name of the DC generator that requires separate excitation? Separately excited generator Compound generator Shunt generator Series generatorQuestion 50 of 56Question 51 of 56 51. 53. What happens if a DC generator is idle for a long time? Increased armature reaction Armature resistance increases Field coil resistance increases Loss of residual magnetismQuestion 51 of 56Question 52 of 56 52. 42. Which voltage is induced dynamically in a DC generator? Direct current voltage Oscillating voltage Pulsating voltage Alternating voltageQuestion 52 of 56Question 53 of 56 53. 56. What causes heavy sparking in DC generator brushes? Excessive brush spring tension Short circuit in field winding Short circuit in armature winding Shift in MNA and GNA positionsQuestion 53 of 56Question 54 of 56 54. 13. What is the name of the part of a DC generator that provides mechanical support and a path for magnetic flux? Pole shoes Stator Yoke (or frame) Pole coreQuestion 54 of 56Question 55 of 56 55. 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 55 of 56Question 56 of 56 56. 1. What is the name of the part marked as 'X' in a DC generator? Armature core Commutator segment Commutator riser BrushQuestion 56 of 56 Loading...
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