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