A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current

Electrical Machines
A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current

Cannot be predicted due to insufficient data.

Would be equal to If1/2.

Would be equal to If1.

Woud be equal to 2If1.

Cannot be predicted due to insufficient data.

Would be equal to If1/2.

Would be equal to If1.

Woud be equal to 2If1.

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Electrical Machines
A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is

1, 2, 3 and 4

3 only

1, 2 and 3

1, 3

1, 2, 3 and 4

3 only

1, 2 and 3

1, 3

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Electrical Machines
The torque developed in IM is nearly proportional to

V2.

1 / V.

V.

1 / V2.

V2.

1 / V.

V.

1 / V2.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Which type of bearing is provided in small induction motors to support the rotor shaft?

None of these

Bush bearings.

Cast iron bearings.

Ball bearings.

None of these

Bush bearings.

Cast iron bearings.

Ball bearings.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then

None of these

I1 > I2

I1 < I2

I1 = I2

None of these

I1 > I2

I1 < I2

I1 = I2

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Electrical Machines
For same HP rating and full load speed which of following motor has poor starting torque?

Shunt.

Series.

Differently compounded.

Cummulative compound.

Shunt.

Series.

Differently compounded.

Cummulative compound.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines

Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is

Electrical Machines The torque developed in IM is nearly proportional to

Electrical Machines Which type of bearing is provided in small induction motors to support the rotor shaft?

Electrical Machines When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then

Electrical Machines For same HP rating and full load speed which of following motor has poor starting torque?

Electrical Machines
A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is

Electrical Machines
The torque developed in IM is nearly proportional to

Electrical Machines
Which type of bearing is provided in small induction motors to support the rotor shaft?

Electrical Machines
When a short circuit test on a transformer is performed at 25 V, 50 Hz, the drawn current is I1. If the test is performed by 25 V and 25 Hz and power drawn current is I2, then

Electrical Machines
For same HP rating and full load speed which of following motor has poor starting torque?