Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them just behind the magnetic neutral axis. just ahead of magnetic neutral axis. in magnetic neutral axis. None of these just behind the magnetic neutral axis. just ahead of magnetic neutral axis. in magnetic neutral axis. None of these 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 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 field winding was wrongly connected there was a break in the armature circuit field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc motor with armature resistance of 0.5 ohms connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 570 A. 460 A. 340 A. 250 A. 570 A. 460 A. 340 A. 250 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum efficiency will occur, when copper loss is_______to iron loss? equal to any of the above greater than less than equal to any of the above greater than less than ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The heat generated in the transformer is dissipated mainly by All of these convection. radiation. conduction. All of these convection. radiation. conduction. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS