DGVCL Exam Paper (11-12-2011)
The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be

90 %
80 %
More than 90%
Less than 90%

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DGVCL Exam Paper (11-12-2011)
The purpose of skewing of rotor slots in an induction motor is

To increase the distributuion factor
To increase the breadth factor
To reduce the magnetic hum of the motor
To reduce the locking tendency of the rotor

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DGVCL Exam Paper (11-12-2011)
The purpose of embedding the damper winding in the pole face of a synchronous motor is to

Eliminate losses on account of fair friction
Eliminate hunting and provide adequate starting torque
Reduce bearing friction
Reduce winding losses

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DGVCL Exam Paper (11-12-2011)
The corona effect can be minimized by increasing

Both spacing between the conductors and diameter of the conductor
The length of the conductor
Spacing between the conductors
Diameter of the conductor

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