Hot questions in Electrical Machines / GO Electrical

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41

GATE Electrical 2016 Set 1 | Question: 48
A three-phase, $50 Hz$ salient-pole synchronous motor has a per-phase direct-axis reactance $(X_{d})$ of $0.8$ pu and a per-phase quadrature-axis reactance $(X_{q})$ of $0.6$ pu. Resistance of the machine is negligible. It is drawing full-load current at $0.8$ pf(leading). When the terminal voltage is $1$ pu, per-phase induced voltage, in pu, is _______.

A three-phase, $50 Hz$ salient-pole synchronous motor has a per-phase direct-axis reactance $(X_{d})$ of $0.8$ pu and a per-phase quadrature-axis reactance $(X_{q})$ of $...

makhdoom ghaya

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makhdoom ghaya asked Jan 29, 2017

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42

GATE Electrical 2016 Set 2 | Question: 43
The starting line current of a $415$ V, $3$-phase, delta connected induction motor is $120$ A, when the rated voltage is applied to its stator winding. The starting line current at a reduced voltage of $110$ V, in ampere, is __________.

The starting line current of a $415$ V, $3$-phase, delta connected induction motor is $120$ A, when the rated voltage is applied to its stator winding. The starting line ...

makhdoom ghaya

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makhdoom ghaya asked Jan 29, 2017

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43

GATE Electrical 2016 Set 1 | Question: 46
A single-phase $400 V, 50 Hz$ transformer has an iron loss of $5000 W$ at the rated condition. When operated at $200 V, 25 Hz$, the iron loss is $2000 W$. When operated at $416 V, 52 Hz$, the value of the hysteresis loss divided by the eddy current loss is _______.

A single-phase $400 V, 50 Hz$ transformer has an iron loss of $5000 W$ at the rated condition. When operated at $200 V, 25 Hz$, the iron loss is $2000 W$. When operated a...

makhdoom ghaya

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makhdoom ghaya asked Jan 29, 2017

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44

GATE Electrical 2016 Set 1 | Question: 47
A $DC$ shunt generator delivers $45 A$ at a terminal voltage of $220 V$. The armature and the shunt field resistances are $0.01 \Omega$ and $44 \Omega$ respectively. The stray losses are $375 W$. The percentage efficiency of the $DC$ generator is _________.

A $DC$ shunt generator delivers $45 A$ at a terminal voltage of $220 V$. The armature and the shunt field resistances are $0.01 \Omega$ and $44 \Omega$ respectively. The ...

makhdoom ghaya

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makhdoom ghaya asked Jan 29, 2017

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45

GATE Electrical 2016 Set 1 | Question: 24
A $4$-pole, lap-connected, separately excited $dc$ motor is drawing a steady current of $40$ A while running at $600$ rpm. A good approximation for the waveshape of the current in an armature conductor of the motor is given by

A $4$-pole, lap-connected, separately excited $dc$ motor is drawing a steady current of $40$ A while running at $600$ rpm. A good approximation for the waveshape of the c...

makhdoom ghaya

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makhdoom ghaya asked Jan 29, 2017

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46

GATE Electrical 2016 Set 1 | Question: 16
In a constant $V/f$ induction motor drive, the slip at the maximum torque Is directly proportional to the synchronous speed. Remains constant with respect to the synchronous speed. Has an inverse relation with the synchronous speed. Has no relation with the synchronous speed.

In a constant $V/f$ induction motor drive, the slip at the maximum torqueIs directly proportional to the synchronous speed.Remains constant with respect to the synchronou...

makhdoom ghaya

9.4k points

makhdoom ghaya asked Jan 29, 2017