Electrical Machines
In a star - delta starting of an IM

  reduced voltage is applied to the stator.
  line voltage is 57.7 % of stator voltage.
  applied voltage per stator phase is 57.7 % of a line volt
  resistance is inserted in the rotor.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Which of the following is done in speed control of DC motor by field flux control?

 Any of above.
 Inserting resistance to armature circuit and field circuit.
 Inserting an additional resistance in the field circuit.
 Inserting an additional resistance in the armature circuit.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements,

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

ANSWER DOWNLOAD EXAMIANS APP