ELECTRICAL MACHINES QUIZ

A single phase, 2 KV alternator has an armature resistance of 0.8 ohms and 4.94 ohms respectively. The voltage regulation of the alternator at 100 a load 0.8 loading power factor is

14%.

0%.

8.9%.

7%.

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YOUR ANSWER : ?

Which of the following pairs is/are correct?

All of these

closed slot----- leakage flux is high

semi closed slot-----leakage flux is moderate

open slot----- leakage flux is less

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Which of the following DC motors has got maximum relieving property?

Series.

Differentical compound.

Shunt.

Cummulative compound.

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The power input to a 3 - φ induction motor is 60 kW and stator loss is 1 kW the rotor cu loss per phase is

slip X 59 / 3.

slip X 69 / 3.

slip X 50 / 3.

1.

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A 8 pole, 50 Hz single phase induction motor is running at 690 rpm. Its slip with respect to forward field is

-0.08

1.92

0.08

-1.92

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A 4 pole 50 Hz induction motor is running at 1470 rpm. Find the speed of stator magnetic field with respect to rotor?

1500 rpm

zero

30 rpm

1470 rpm

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Rotor resistance speed control is used in

dc shunt motor.

synchronous motor.

slip ring induction motor.

squirrel cage induction motor.

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The stator frame in an induction motor is used to

hold armature stamping in position.

ventilate the armature.

provide return path for the flux.

protect the whole machine.

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In an alternator, voltage drops occurs in

armature resistance, leakage reactance, armature reaction and earth connection.

armature resistance and leakage reactance.

armature resistance, leakage reactance and armature reaction.

armature resistance only.

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YOUR ANSWER : ?

Field weakening control method is used for the _________ ?

above rated speed

below rated speed

None of these

both A and B

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YOUR ANSWER : ?

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