. A bridge circuit is used to measure the loss of larger transformers because the circuit A. promotes safety. B. eliminates calculations. C. increases measuring convenience. D. improves measurement accuracy. 13.b. A synchronous machine is run as an unloaded motor. If a low voltage is supplied at the rated frequency, and if the full-load armature current flows, a test is being run to determine the A. windage loss. B. I²R loss. C. stray-load loss. D. core loss.
Synchronous Generator
In comparison to an asynchronous generator, it is a machine where the rotor speed is equal to the rotating magnetic field produced by the stator, i.e., mechanical speed is equal to the electrical speed, thus called synchronous, and not asynchronous.
Salient Pole Rotor
Salient pole rotor includes a large number of exposed poles mounted on a magnetic wheel. The construction of a bright pole is as shown in the image on the left. The proposed poles are made of metal laminations. The rotor winding is provided on these poles and is supported by pole shoes.
13.a. A bridge circuit is used to measure the loss of larger transformers because the circuit
A. promotes safety.
B. eliminates calculations.
C. increases measuring convenience.
D. improves measurement accuracy.
13.b. A synchronous machine is run as an unloaded motor. If a low voltage is supplied at the rated
frequency, and if the full-load armature current flows, a test is being run to determine the
A. windage loss.
B. I²R loss.
C. stray-load loss.
D. core loss.
A synchronous electric motor is an AC motor in which the shaft rotation is synchronised with the frequency of the supply current at steady state[1], and the rotation period is an integral number of AC cycles. Synchronous motors have multiphase AC electromagnets on the stator that generate a magnetic field that rotates in time with the line current oscillations. The rotor, which is made up of permanent magnets or electromagnets, rotates at the same rate as the stator field, resulting in the second synchronised revolving magnet field of any AC motor.If both the rotor and stator of a synchronous motor are supplied with independently excited multiphase AC electromagnets, it is referred to as doubly fed.
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