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