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