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