Electrical Machines The armature core of the rotor bars of dc motors are laminated to reduce hysteresis loss. to provide better flux linkage. to reduce eddy current loss. to reduce mechanical losses. to reduce hysteresis loss. to provide better flux linkage. to reduce eddy current loss. to reduce mechanical losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To eliminate the 5th harmonic in the induced voltages their respective pitch factor angle should be 18° 72° 30° 36° 18° 72° 30° 36° ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will remain the same. It will be doubled. It will becomes four times. It will be halved. It will remain the same. It will be doubled. It will becomes four times. It will be halved. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Terminal voltage is same Speed of alternators should be same Both 1and 2 Frequency should be same Terminal voltage is same Speed of alternators should be same Both 1and 2 Frequency should be same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux involved in the emf equation of a transformer has maximum value. average value. total value. rms value. maximum value. average value. total value. rms value. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS