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. 0.443. 0.512. 0.649. 0.573. 0.443. 0.512. 0.649. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A simple method of increasing the voltage of a DC generator is to increase the source frequency. increase the number of turns in armature coil. increase the speed of shaft rotation. increase the number of turns in field coil. increase the source frequency. increase the number of turns in armature coil. increase the speed of shaft rotation. increase the number of turns in field coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 44 A. 40 A. 440 A. 400 A. 44 A. 40 A. 440 A. 400 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The output power of a dc motor is given by none of these. EbIa. EIa. EbIa2. none of these. EbIa. EIa. EbIa2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around unity 0.2 lag 0.9 lag 0.2 lead unity 0.2 lag 0.9 lag 0.2 lead ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For high current and low current rating which winding is employed to DC machine? None of above Lap winding Wave winding Both lap and wave winding None of above Lap winding Wave winding Both lap and wave winding ANSWER DOWNLOAD EXAMIANS APP