## Electrical Machines The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are

1, 2, 3, 4 and 5
2, 3, 4, 5
2, 3, 4
1, 3, 4, 5

K×R1
R1 /K²
K²R1
R1 /K

## Electrical Machines Consider the following statements: To control the speed of a dc shunt motor above the base speed over a reasonably wide range, the motor must 1. have compensating winding 2. have interpole winding 3. be started using a 3-point starter 4. be started using a 4-point starter Of these statements

1, 2 and 3 are correct
1, 2 and 4 are correct
1 and 3 are correct
2 and 4 are correct

0.7.
0.3.
0.54.
1.

## Electrical Machines In a synchronous machine, if the field flux axis is ahead of the armature field axis in the direction of rotation, the machine operating is

asynchronous motor.
synchronous motor.
asynchronous generator.
synchronous generator.

R2 = s2X2.
R2 = s2X2.
R2 = sX2.
sR2 = X2.