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For a given stepper motor, which of the following torque has the highest numerical value ?
A) Pullin torque B) Pullout torque C) Holdingtorque D) Detent torque

The interpoles in DC machines have a tapering shape in order to

A) reduce the overall weight

) increase the acceleration of commutation

) reduce the saturation in the interpoles

) economics on the material required for interpoles and their windings

GOD

If two 8-pole DC machines of identical armature are wound, one with lap winding and the
other with wave winding, then

A) wave wound machine will have more rated current and more voltage
B) lap wound machine will have more rated voltage and more current
C) lap wound machine will have more rated voltage and less current

D) wave wound machine will have more rated voltage and less current

If the speed of a DC motor increases with load torque, then it isa
A
B
௦
D

series motor

permanent magnet motor
differentially compounded motor
cumulatively compounded motor

)
)
)
)

ADC shunt motor having unsaturated magnetic circuit runs at 1500 rpm with rated voltage.
If the applied voltage is half of rated voltage, the motor will run at

A) 750 rpm B) 1000 rpm C) 1200 rpm D) 1500 rpm

A DC shunt motor has external resistances of R, and R, in the armature and field circuits
respectively. Armature current at starting can be reduced by keeping

A) R, maximum and Ry minimum B) R, maximum and R, maximum
C) R, minimum and Ry minimum D) Rymaximum and R, minimum

An electric train employing a DC series motor is running at a fixed speed. When a sudden
slight drop in the mains voltage occurs, what result will occurs ?

A) rise in speed and drop in current
B) drop in speed and rise in current
C) rise in speed and rise in current
D) drop in speed with current unaltered

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