By Surendra | June 10, 2020 0 Comment 0% 4 Created by Surendra DC Generators Quiz in English Set 1 All Important Question Answers for Electrician Related Exams 1 / 25 The e.m.f. generated in a D.C. generator is directly proportional to all of the above number of poles flux/pole speed of armature 2 / 25 In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis when the generator runs on full load the generator runs on designed speed there is no load on|he generator the generator runs on overload 3 / 25 In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when r.p.m. is less than 300 r.p.m. is more than 300 number of poles is 2 number of poles is 4 4 / 25 The bearings used to support the rotor shafts are generally needle bearings bush bearings ball bearings magnetic bearmgs 5 / 25 Lamination’s of core are generally made of stainless steel carbon case iron silicon steel 6 / 25 Iron losses in a D.C. machine are independent of variations in voltage load speed speed and voltage 7 / 25 In D.C. generators the pole shoes are fastened to the pole core by counter sunk screws rivets brazing welding 8 / 25 A separately excited generator as compared to a self-excited generator is more stable has all above features has exciting current independent of load current is amenable to better voltage control 9 / 25 In case of D.C. machines mechanical losses are primary function of current speed none of above voltage 10 / 25 In a four-pole D.C. machine alternate poles are north and south two north poles follow two south poles all the four poles are north poles all the four poles are south poles 11 / 25 Fleming’s right-hand rule regarding direction of induced e.m.f. correlates magnetic flux direction of current flow and resultant force magnetic flux direction of force and direction of motion of conductor magnetic field strength induced voltage and current magnetic flux direction of motion and the direction of e.m.f. induced 12 / 25 The commutator segments are connected to the armature conductors by means of insulation pads copper lugs resistance wires brazing 13 / 25 The armature of D.C. generator is laminated to insulate the core reduce the bulk provide the bulk reduce eddy current loss 14 / 25 For a D.C. generator when the number of poles and the number of armature conductors is fixed then which winding will give the higher e.m.f. ? Either of and above Lap winding Wave winding Depends on other features of design 15 / 25 Copper brushes in D.C. machine are used in both of the above cases where low voltage and high currents are involved in none of the above cases where high voltage and small cur-rents are involved 16 / 25 In D.C. generators the cause of rapid brush wear may be severe sparking rough commutator surface imperfect contact any of the above 17 / 25 Which of the following could be lamina-proximately the thickness of lamination’s of a D.C. machine ? 0.5 mm 5 mm 0.005 mm 0.05 mm 18 / 25 In lap winding the number of brushes is always half the number of poles double the number of poles same as the number of poles two 19 / 25 While applying Fleming’s right-hand rule to And the direction of induced e.m.f. the thumb points towards direction of flux direction of induced e.m.f. direction of motion of conductor if forefinger points along the lines of flux direction of motion of the conductor if forefinger points in the direction of generated e.m.f. 20 / 25 In D.C. generators the polarity of the interpoles is opposite to that of the main pole ahead is the same as that of the immediately preceding pole is neutral as these poles do not play part in generating e.m.f. is the same as that of the main pole ahead 21 / 25 In a commutator copper is harder than mica mica and copper are equally hard mica is harder than copper none of the above 22 / 25 The field coils of D.C. generator are usually made of copper mica cast iron carbon 23 / 25 According to Fleming’s right-hand rule for finding the direction of induced e.m.f. when middle finger points in the direction of induced e.m.f. forefinger will point in the direction of either of the above motion of conductor lines of force none of the above 24 / 25 Permeance is the reciprocal of flux density ampere-turns resistance reluctance 25 / 25 The resistance of armature winding depends on all of the above cross-sectional area of the conductor number of conductors length of conductor कृपया सही सूचना भरें ताकि सर्टिफिकेट ईमेल पर भेजा जा सकें। NameEmailPhone NumberDistrictSchool/Coaching Name Your score is LinkedIn Facebook VKontakte 0% Restart quiz आपको यह क्विज अच्छी लगी तो 5 स्टार रेटिंग जरुर दें । Send feedback
