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