Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Remains unchanged. Decreases. Increases. Oscillates around the rated speed. Remains unchanged. Decreases. Increases. Oscillates around the rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be more than core loss. zero. equal to core loss. less than core loss. more than core loss. zero. equal to core loss. less than core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When excitation is increased (over excitation), the synchronous generator operates at leading power factor. unity power factor. lagging power factor. any of the above. leading power factor. unity power factor. lagging power factor. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalanced supply voltage given to a 3 - φ, delta connected induction motor will cause all of these. less heating of the rotor. less heating of the rotor. negative sequence current. all of these. less heating of the rotor. less heating of the rotor. negative sequence current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to with stand Any unbalanced magnetic pull on the armature core. All of these Bending moment due to weight of the armature. Twisting stains due to transmission of torque. Any unbalanced magnetic pull on the armature core. All of these Bending moment due to weight of the armature. Twisting stains due to transmission of torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 200 V 230 V 460 V 115 V 200 V 230 V 460 V 115 V ANSWER DOWNLOAD EXAMIANS APP