1-Which of the following sentences is wrong? (why) a-) The difference between the speed of the...

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Electrical Engineering

1-Which of the following sentences is wrong? (why)

a-) The difference between the speed of the rotating field andthe rotor speed in the synchronous motor is zero,

b-) The difference between the synchronous motor and theasynchronous motor is that the rotor is fed with alternatingcurrent from the outside,

c-) Synchronous motor and asynchronous motor can be used asgenerators,

d-) Synchronous motor and foreign excited motor are similar.

2-Which of the following sentences is true? (why)

a-) Asynchronous motor secondary with ring works like an opentransformer,

b-) In order to give a star delta to the asynchronous motor, themains voltage must be one of the phase voltage of the motor,

c-) Overcurrent role is connected between the U-V, V-W and W-Uwindings before the motor, in order to be easy to protect inasynchronous motors,

d-) The speed of the rotor is equal to the synchronous speed inasynchronous motors with power less than 2.2 kW. In the big, it islow.

3-Which of the following is wrong? (why)

a-) The most common form of starting in ring asynchronous motorsis star / delta starting,

b-) To change the direction of rotation of the asynchronousmotor, it is enough to change the positions of the R and Sphases,

c-) If the operating voltage of the motor's phase winding issuitable for the mains voltage, motors with a power less than 3 KWcan be triangularly connected,

d-) Asynchronous motor can be made by changing the rotor of theasynchronous motor.

4-Which of the following is wrong? (why)

a-) Every electric machine can generate voltage,

b-) The highest voltage occurring in the rotor in a 6 pole, 60Hz induction motor is when the rotor rotates at 1200 rpm.

c-) In the application, lever, pako, automatic, electronic startriangle switches are used,

d-) Stator iron losses are always higher than rotor iron lossesin the asynchronous motor.

5-) Pako star triangle switch; (why)

a-) There are 3 connection screws, b-) 3 + 3 = 6 connectors, d-)There are 9 connectors, e-) 11 + 1 = 12

there are connection ends, e-) 6 + 1 = 7 connection ends.

6-) Time role is not used in which of the following? (why)

a-) Changing the direction of rotation,

b-) Starting asynchronous motor with ring,

c-) Asynchronous motors In resistance starting, d-) star-deltaoperation,

e-) asynchronous motors with reactance (coil) In decisionmaking.

7-) Which of the following sentences contains wrong provisions?(why)

a-) voltage is induced in the rotor winding of the synchronousmotor,

b-) voltage in the rotor of the asynchronous motor induced,

c-) the speed of the asynchronous motor depends on the number ofpoles,

d-) the rotating field in the asynchronous motor There is also asynchronous motor.

8-) 3 ohms are measured with an ohmmeter between the V-W ends ofa star connected synchronous generator. according to the effectiveresistance of a phase; (why)

a-) 1.5 Ω, b-) 3 Ω, c-) 2.5 Ω, d-) 0.75 Ω, e-) 2.25 Ω our.

9-) Which of the following sentences makes the wrong judgment?(why)

a-) the voltage generating mechanism of synchronous generatorsis different from that of DA machines,

b-) synchronous rotor speed in the generator can be found as thespeed of the asynchronous motor,

c-) squirrel cage asynchronous motor can be used asgenerator,

d-) synchronous machines have opposite emf in rotor it doesnot.

10- Capacitive operation with synchronous motor ……………………………… ..………………… ...

a-) connecting capacitor to phase winding ends …………… .. isprovided,

b-) rotating area of ​​rotor speed more than the number ofrevolutions ……………… .. it may be possible,

c-) the excitation current is too high may be possible with…………………,

d-) the speed and the excitation current lowering can beachieved with ……………………….,

e-) in the opposite direction of the rotating field direction ofthe rotor to the rotating field speed.............................. rotation can.

Answer & Explanation Solved by verified expert
4.4 Ratings (961 Votes)
1 b TheTdifference between Synchronous motor and asynchronous motor is that the rotor of synchronous motor are excited by DC source and not by AC source 2 b One of the necessary condition for an asynchronous motor to be started with a star delta starter is that the main    See Answer
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