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