DGVCL Exam Paper (11-12-2011)
DC series motors are best suited for traction work because

Torque and speed are inversely proportional to the square of the armature current
Its torque is proportional to the square of the armature current and speed is directional proporational to torque
Its torque is proportional to the square of the armature current and speed is inversely proportional to torque
Torque and speed are proportional to the square of the armature current

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

DGVCL Exam Paper (11-12-2011)
The purpose of interpoles in DC machines is to nullify

The cross-magnetizing effect of armature mmf
The reactance voltage
The demagnetizing effect of armature mmf
Both the cross-magnetizing mmf and the reactance voltage

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

DGVCL Exam Paper (11-12-2011)
Distribution transformers have good all day efficiency due to

Low copper loss
Low iron loss
Low voltage
Low copper as well as iron loss

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

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

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

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP

DGVCL Exam Paper (11-12-2011)
The main advantage of using fractional pitch winding is to refuce

Cost of the machine
Size of the machine
Amount of copper in the winding
Harmonics in the generated emf

ANSWER EXPLANATION DOWNLOAD EXAMIANS APP