Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the motor may run away. the starting torque becomes low. the motor may not start. the starting current will be enormously high. the motor may run away. the starting torque becomes low. the motor may not start. the starting current will be enormously high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. The frequency of rotor current is 5 Hz 50 Hz 0 Hz 1 Hz 5 Hz 50 Hz 0 Hz 1 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation of the synchronous generator fails, it acts as a/an induction motor. synchronous generator. induction generator. synchronous motor. induction motor. synchronous generator. induction generator. synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When applied rated voltage per phase is reduce to one half, the starting torque of three phase squirrel cage induction motor becomes 1/2 of the initial value 4 time the initial value twice the initial value 1/4 of the intial value 1/2 of the initial value 4 time the initial value twice the initial value 1/4 of the intial value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator the brushes of opposite polarity should track each other. brush position has no effect on the commutator grooving. None of these the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. brush position has no effect on the commutator grooving. None of these the brushes of same polarity should track each other. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. ANSWER DOWNLOAD EXAMIANS APP