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. 0.443. 0.649. 0.512. 0.573. 0.443. 0.649. 0.512. 0.573. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat generated in the transformer is dissipated mainly by All of these conduction. convection. radiation. All of these conduction. convection. radiation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Counter emf of a DC motor aids applied voltage. regulates its armature voltage. helps in energy conversion. exceeds supply voltage aids applied voltage. regulates its armature voltage. helps in energy conversion. exceeds supply voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If field current is decreased in shunt dc motor, the speed of the motor remains same. decreases. increases. None of these remains same. decreases. increases. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the phase difference between two windings of A.C servomotor ? 120°. 60°. 30°. 90°. 120°. 60°. 30°. 90°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 100 Hz 0 Hz 25 Hz 50 Hz 100 Hz 0 Hz 25 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP