Electrical Machines The synchronous speed of an induction motor will be increased by decreasing of frequency. speed can not be increased. increasing of frequency. increasing number of poles. decreasing of frequency. speed can not be increased. increasing of frequency. increasing number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1080 1000 1203 1200 1080 1000 1203 1200 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by cooling the armature. increasing the input to the prime mover. increasing the excitation. reducing the load voltage. cooling the armature. increasing the input to the prime mover. increasing the excitation. reducing the load voltage. 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 becomes four times. It will remain the same. It will be halved. It will be doubled. It will becomes four times. It will remain the same. It will be halved. It will be doubled. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat transfer by convection in a transformer least depends on surface area. air velocity. temperature difference. color of the paint. surface area. air velocity. temperature difference. color of the paint. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 625 W 650 W 600 W 700 W 625 W 650 W 600 W 700 W ANSWER DOWNLOAD EXAMIANS APP