Electrical Machines An ideal synchronous motor has no starting torque because relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. rotor is made up of salient poles. relative velocity between stator and rotor mmf’s is not zero. rotor winding is highly reactive. relative velocity between the stator and rotor mmf’s is zero. rotor is made up of salient poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Satisfactory commutation of DC machine requires All of these brushes should smoothly run in the holders. brushes should be of proper grade and size. smooth, concentric commutator properly undercut. All of these brushes should smoothly run in the holders. brushes should be of proper grade and size. smooth, concentric commutator properly undercut. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. damping torque. restoring torque. mechanical rotatory system. synchronizing power co efficient. damping torque. restoring torque. mechanical rotatory system. synchronizing power co efficient. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side lags by -30°. Star side lags by -30°. Delta side leads by 30°. Star side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Delta side leads by 30°. Star side leads by 30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 4 pole, 50 Hz induction motor 4 % slip, calculate frequency of the rotor emf? 3 Hz. 50 Hz. 10 Hz. 2 Hz. 3 Hz. 50 Hz. 10 Hz. 2 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. back emf is equal to applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. back emf is equal to applied voltage. none of above. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS