By Surendra | June 11, 2020 0 Comment 0% 0 Created by Surendra 3 Phase Induction Quiz in English Set 1 All Important Question Answers for Electrician Related Exams 1 / 20 DOL starting of induction motors is usually restricted to low horsepower motors high speed motors variable speed motors high horsepower motors 2 / 20 In case of the induction motors the torque is directly proportional to (slip)2 inversely proportional to (Vslip) inversely proportional to slip directly proportional to slip 3 / 20 The speed of a squirrel-cage induction motor can be controlled by all of the following except changing winding resistance reducing supply voltage changing supply frequency changing number of poles 4 / 20 Size of a high speed motor as compared to low speed motor for the same H.P. will be bigger same smaller any of the above 5 / 20 Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor ? By injecting e.m.f. in the rotor circuit Rotor rheostat control By changing the number of stator poles By operating two motors in cascade 6 / 20 When the equivalent circuit diagram of doouble squirrel-cage induction motor is constructed the two cages can be considered in parallel in series in series-parallel in parallel with stator 7 / 20 The crawling in the induction motor is caused by improper design of the machine low voltage supply harmonics developed in the motor high loads 8 / 20 In medium sized induction motors the slip is generally around 0.0004 0.004 0.04 0.14 9 / 20 In the circle diagram for induction motor the diameter of the circle represents line voltage running torque slip rotor current 10 / 20 Stepless speed control of induction motor is possible by which of the following methods ? Cascade operation E.M.F. injection in rotor circuit Changing the number of poles None of the above 11 / 20 A 3-phase induction motor stator delta connected is carrying full load and one of its fuses blows out. Then the motor will continue running without any harm to the winding will continue running burning its two phases will stop and carry heavy current causing permanent damage to its winding will continue running burning its one phase 12 / 20 The maximum torque in an induction motor depends on frequency all of the above square of supply voltage rotor inductive reactance 13 / 20 Which of the following component is usually fabricated out of silicon steel ? Shaft None of the above Stator Core Bearings 14 / 20 The auto-starters (using three auto transformers) can be used to start cage induction motor of the following type and both star connected only delta connected only none of the above 15 / 20 The shaft of an induction motor is made of stiff flexible any of the above hollow 16 / 20 The shaft of an induction motor is made of high speed steel stainless steel carbon steel cast iron 17 / 20 The frame of an induction motor is usually made of aluminium silicon steel cast iron bronze 18 / 20 For which motor the speed can be controlled from rotor side ? Squirrel-cage induction motor Slip-ring induction motor Both and (2) None of the above 19 / 20 A double squirrel-cage induction motor has two parallel windings in rotor two series windings in stator two parallel windings in stator two rotors moving in oppsite direction 20 / 20 The injected e.m.f. in the rotor of induction motor must have the same phase as the rotor e.m.f. the same frequency as the slip frequency zero frequency high value for the satisfactory speed control 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
