SYNCHRONOUS MOTOR :A synchronous motor is one in which the rotor normally rotates at the same speed as the revolving field in the machine. The stator is similar to that of an induction machine consisting of a cylindrical iron frame with windings, usually three-phase, located in slots around the inner periphery. Objective Questions Short notes Objective questions (Answers are given … Read more
MCQ ON ALTERNATORS Objective Questions Short notes Objective questions (Answers are given below) The frequency of voltage generated by an alternatorhaving 4-poles and rotating at 1800 r.p.m.is …….hertz.(a) 60 (b) 7200(c) 120 (d) 450. A 50-Hz alternator will run at the greatestpossible speed if it is wound for ……. poles.(a) 8 (b) 6(c) 4 (d) … Read more
Objective Questions Short notes Objective questions (Answers are given below) The starting winding of a single-phase motoris placed in the(a) rotor (b) stator(c) armature (d) field. One of the characteristics of a single- phasemotor is that it(a) is self-starting(b) is not self-starting(c) requires only one winding(d) can rotate in one direction only. After the starting … Read more
Objective Questions Short notes Objective questions (Answers are given below) 1.In the circle diagram for a 3-φ induction motor,the diameter of the circle is determined by(a) rotor current(b) exciting current(c) total stator current(d) rotor current referred to stator. Answer : C 2.Point out the WRONG statement.Blocked rotor test on a 3-φ induction motorhelps to find(a) … Read more
Objective Questions Short notes Objective questions (Answers are given below) Regarding skewing of motor bars in a squirrelcageinduction motor, (SCIM) which statementis false ?(a) it prevents cogging(b) it increases starting torque(c) it produces more uniform torque(d) it reduces motor ‘hum’ during its operation. The principle of operation of a 3-phase. Inductionmotor is most similar to … Read more