Q3/ Chose the correct answer for the following1. Synchronous motors are generally not self-starting because(a) the direction of rotation is not fixed(b) the direction of instantaneous torque reverses after half cycle(c) startes cannot be used on these machines(d) starting winding is not provided on the machines2. The power developed by a synchronous motor will be maximum when the loadangle is(a) Zero(b) 45°(c) 90°(d) 120°3. An over-excited synchronous motor takes(a) leading current(b) lagging current(c) both (a) and (b)(d) none of the above4. In a synchronous motor, the magnitude of stator back e.m.f. £& depends on(a) d.c. excitation only(b) speed of the motor(c) load on the motor(d) both the speed and rotor flux5. A pony motor is basically a(a) small induction motor (c) D.C. shunt motor(b) D.C. series motor (d) double winding A.C./D.C. motor

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Q3/ Chose the correct answer for the following 1. Synchronous motors are generally not self-starting because (a) the direction of rotation is not fixed (b) the direction of instantaneous torque reverses after half cycle (c) startes cannot be used on these machines (d) starting winding is not provided on the machines 2. The power developed by a synchronous motor will be maximum wher angle is (a) Zero (b) 45° (c) 90° (d) 120° 3. An over-excited synchronous motor takes (a) leading current (b) lagging current (c) both (a) and (b) (d) none of the above 4. In a synchronous motor, the magnitude of stator back e.m.f. £& depene (a) d.c. excitation only (b) speed of the motor (c) load on the motor (d) both the speed and rotor flux

Q3/ Chose the correct answer for the following 1. Synchronous motors are generally not self-starting because (a) the direction of rotation is not fixed (b) the direction of instantaneous torque reverses after half cycle (c) startes cannot be used on these machines (d) starting winding is not provided on the machines 2. The power developed by a synchronous motor will be maximum wher angle is (a) Zero (b) 45° (c) 90° (d) 120° 3. An over-excited synchronous motor takes (a) leading current (b) lagging current (c) both (a) and (b) (d) none of the above 4. In a synchronous motor, the magnitude of stator back e.m.f. £& depene (a) d.c. excitation only (b) speed of the motor (c) load on the motor (d) both the speed and rotor flux

Electricity for Refrigeration, Heating, and Air Conditioning (MindTap Course List)

10th Edition

ISBN:9781337399128

Author:Russell E. Smith

Publisher:Russell E. Smith

Chapter14: Troubleshooting Electric Control Devices

Section: Chapter Questions

Problem 2RQ

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