Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.649. 0.512. 0.443. 0.573. 0.649. 0.512. 0.443. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is suitable for frequent starting and stoppings? Resistance split phase motor Capacitor start motor Capacitor start capacitor run motor All of these Resistance split phase motor Capacitor start motor Capacitor start capacitor run motor All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are not a self starting motor? 1-phase induction motor None of these 3-phase induction motor both 1 and 2 1-phase induction motor None of these 3-phase induction motor both 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance there was no residual magnetism in the field circuit field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to armature emf. None of these reactance voltage induced in the coil. coil resistance. armature emf. None of these reactance voltage induced in the coil. coil resistance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of rotor current of 50 Hz induction motor operating at 4% slip? 50Hz 1 Hz 2.5Hz 2HZ 50Hz 1 Hz 2.5Hz 2HZ ANSWER DOWNLOAD EXAMIANS APP