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