Recent questions tagged rotor

Description : The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be

Last Answer : The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be 0.5 Ohm

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

Description : Ratio of the rotor reactance X to the rotor resistance R for a two-phase servo motor (A) is equal to that of a normal induction motor (B) is less than that of a normal induction motor (C) ... than that of a normal induction motor (D) may be less or greater than that of a normal induction motor

Last Answer : C

Last Answer : The bearings used to support the rotor shafts are generally ball bearings.

Last Answer : Locked rotor current of a shaded pole motor is slightly more than full load current.

Last Answer : The rotor of a hysteresis motor is made of chrome steel.

Last Answer : In a hysteresis motor, the rotor must have retentivity.

Last Answer : The rotor developed by a single-phase motor at starting is zero.

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Description : Salient pole rotor is use for which speed?

Last Answer : Salient pole rotor is use for low and medium speed prime movers.

Description : Which rotor is use for high speed in turbo alternators?

Last Answer : Non-salient pole rotor is used for high speed in turbo alternators.

Description : An electric motor in which both stator field and rotor rotates with same speed is called?

Last Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.

Description : What is the rotor of a motor?

Last Answer : Rotor is the rotating or moving part in motor and generator.