## Electrical Machines Interpoles in a DC motor must be

Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature.
Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature.
Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature.
Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature.

## Electrical Machines The direction of rotation of a 3 - ÃŽÂ¦ induction motor is clockwise when it is supplied with 3 - ÃŽÂ¦ sinusoidal voltage having phase sequence A - B - C. For counterclockwise rotation of motor, the phase sequence of the supply should be

C - A - B.
A - C - B.
B - C - A or C - A - B.
B - C - A.

## Electrical Machines In DC generators brushes are used for

collecting of current without any sparkings
convert ac armature current in to dc
collecting of voltage
reduce eddy current loss

## Electrical Machines Find the developed torque DC Series Motor having armature resistance of 0.2 Ω and taking armature current of 60 A is connected to 250 V supply. Considered brush drop of 1 V each.

234.76 N-m.
133.22 N-m
266.20 N-m.
cant be determined.

## Electrical Machines For higher values of armature, the speed of a DC series motor is

Proportional to armature current.
Proportional to the square of armature current.
Inversely proportional to armature current.
Constant.

## Electrical Machines Which of the following statements is/are correct statements?

EMF per turn in both the windings are equal
EMF per turn in HV winding is less than EMF per turn in LV winding
All of these
EMF per turn in HV winding is more than EMF per turn in LV winding