Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating winding are used to rectify the flux density waveform at None of these interpole region. region under main pole. throughout the air gap. None of these interpole region. region under main pole. throughout the air gap. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is Fmax. 3Fmax. (3/2)Fmax. (1/2)Fmax. Fmax. 3Fmax. (3/2)Fmax. (1/2)Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by compensating winding and commutating poles. increasing field excitation. fixing the brush axis inline with the pole axis. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. increasing field excitation. fixing the brush axis inline with the pole axis. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In travelling cranes for crane travel, trolley and boom hoist which motor is preferred? Synchronous motor. Slip ring induction motor. DC differential compound motor. Stepper motor. Synchronous motor. Slip ring induction motor. DC differential compound motor. Stepper motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - φ induction motor running at full load which of these parameters is stationary with respect to the stator mmf wave? Stator winding. Rotor mmf wave. Both rotor and stator winding. Rotor winding. Stator winding. Rotor mmf wave. Both rotor and stator winding. Rotor winding. ANSWER DOWNLOAD EXAMIANS APP
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