Electrical Machines In travelling cranes for hoisting and lowering which type of motor is preferred? DC series motor. Single phase induction motor. Synchronous motor. AC slip ring motor. DC series motor. Single phase induction motor. Synchronous motor. AC slip ring motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 4 Ω. 8 Ω. 10 Ω. 2 Ω. 4 Ω. 8 Ω. 10 Ω. 2 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. The frequency of rotor current is 1 Hz 0 Hz 5 Hz 50 Hz 1 Hz 0 Hz 5 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the starting current will be enormously high. the starting torque becomes low. the motor may run away. the motor may not start. the starting current will be enormously high. the starting torque becomes low. the motor may run away. the motor may not start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the developed torque DC Series Motor having armature resistance of 0.2 Ω and taking armature current of 60 A is connected to 250 V supply. Considered brush drop of 1 V each. 133.22 N-m cant be determined. 234.76 N-m. 266.20 N-m. 133.22 N-m cant be determined. 234.76 N-m. 266.20 N-m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere. None of these. 220.4 volt. 120 volt. 218.5 volt. None of these. 220.4 volt. 120 volt. 218.5 volt. ANSWER DOWNLOAD EXAMIANS APP
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