Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 40% 19% 10% 5% 40% 19% 10% 5% ANSWER DOWNLOAD EXAMIANS APP
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) changes to 0.5 times the original value changes to three times the original value remain the same as the original changes to 1.5 times the original value changes to 0.5 times the original value changes to three times the original value remain the same as the original changes to 1.5 times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is critical, the power factor of the alternator is leading power factor. unity power factor. lagging power factor. None of these leading power factor. unity power factor. lagging power factor. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Air core transformer as compared to iron core transformer, has more copper loss. less magnetic core loss. more magnetic core loss. no magnetic core loss. more copper loss. less magnetic core loss. more magnetic core loss. no magnetic core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V dc series generator is driven at its rated speed. The no-load voltage across its armature terminals would be 230 V somewhat less than 230 V 6 V somewhat more than 230 V 230 V somewhat less than 230 V 6 V somewhat more than 230 V ANSWER DOWNLOAD EXAMIANS APP