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 In a D.C. generator the magnetic neutral axis coincides with the geometrical neutral axis when the generator runs on designed speed there is no load on|he generator the generator runs on full load the generator runs on overload 2 / 25 A separately excited generator as compared to a self-excited generator has all above features is amenable to better voltage control is more stable has exciting current independent of load current 3 / 25 In case of D.C. machines mechanical losses are primary function of voltage speed current none of above 4 / 25 Lamination’s of core are generally made of case iron stainless steel carbon silicon steel 5 / 25 In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when number of poles is 2 r.p.m. is less than 300 number of poles is 4 r.p.m. is more than 300 6 / 25 In lap winding the number of brushes is always double the number of poles half the number of poles same as the number of poles two 7 / 25 Permeance is the reciprocal of reluctance resistance flux density ampere-turns 8 / 25 The e.m.f. generated in a D.C. generator is directly proportional to number of poles flux/pole speed of armature all of the above 9 / 25 Which of the following could be lamina-proximately the thickness of lamination’s of a D.C. machine ? 0.5 mm 0.005 mm 0.05 mm 5 mm 10 / 25 The armature of D.C. generator is laminated to insulate the core provide the bulk reduce the bulk reduce eddy current loss 11 / 25 Copper brushes in D.C. machine are used in none of the above cases where low voltage and high currents are involved in both of the above cases where high voltage and small cur-rents are involved 12 / 25 Iron losses in a D.C. machine are independent of variations in speed and voltage speed load voltage 13 / 25 In a commutator none of the above copper is harder than mica mica is harder than copper mica and copper are equally hard 14 / 25 The resistance of armature winding depends on number of conductors cross-sectional area of the conductor length of conductor all of the above 15 / 25 In D.C. generators the pole shoes are fastened to the pole core by welding counter sunk screws rivets brazing 16 / 25 In D.C. generators the cause of rapid brush wear may be any of the above imperfect contact severe sparking rough commutator surface 17 / 25 In a four-pole D.C. machine alternate poles are north and south all the four poles are north poles two north poles follow two south poles all the four poles are south poles 18 / 25 In D.C. generators the polarity of the interpoles is the same as 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 opposite to that of the main pole ahead 19 / 25 The commutator segments are connected to the armature conductors by means of copper lugs brazing resistance wires insulation pads 20 / 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 Depends on other features of design Lap winding 21 / 25 The bearings used to support the rotor shafts are generally ball bearings needle bearings bush bearings magnetic bearmgs 22 / 25 The field coils of D.C. generator are usually made of carbon cast iron mica copper 23 / 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 motion of the conductor if forefinger points in the direction of generated e.m.f. direction of induced e.m.f. direction of motion of conductor if forefinger points along the lines of flux 24 / 25 Fleming’s right-hand rule regarding direction of induced e.m.f. correlates magnetic flux direction of force and direction of motion of conductor magnetic flux direction of motion and the direction of e.m.f. induced magnetic field strength induced voltage and current magnetic flux direction of current flow and resultant force 25 / 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 motion of conductor lines of force 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
