ELECTRICAL MACHINES QUIZ

The speed regulation of a DC motor is given as

(NfL − NnL)/NnL.

NnL/NfL.

NnL − NfL.

(NnL − NfL)/NfL.

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Which single phase motor is used for a refrigerator?

Split phase.

Capacitor run.

Universal.

Repulsion.

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In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will

improve but terminal voltage will fall.

worsen and terminal voltage will fall

improve and terminal voltage will rise .

worsen and terminal voltage will rise.

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In a DC machine, which of these parameters remain the same whether it runs as a DC motor or a DC generator?

Can not be determined.

Armature current.

Mechanical power.

Induced emf.

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A 3 - ÃŽÂ¦, 6 pole, 50 Hz IM is running at a full load speed of 980 rpm. If it delivers an air gap power of 98000 Watt, calculate the rotor ohmic loss?

1960 Watt.

1920 Watt.

980 Watt.

1800 Watt.

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Total core loss is also called as -------------?

Hysteresis loss

Copper loss

Magnetic loss

Eddy current loss

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In double cage induction motor, the outer cage offers

low resistance and low reactance.

low resistance and high reactance.

high resistance and high reactance.

high resistance and low reactance.

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The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is

44 A.

40 A.

400 A.

440 A.

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In normal dc machines operating at full-load conditions, the most powerful electromagnet is

interpole winding

field winding

armature winding

interpole and compensating windings together

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If the field current is reduced to zero the maximum power developed by alternator is

2.73 KW.

1.644 KW.

5.46 KW.

0.9103 KW.

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