DC Motors Which of the following losses are significantly reduced by laminating the core of a D.C. generator? Hysteresis losses Eddy current losses Copper losses Windage losses Hysteresis losses Eddy current losses Copper losses Windage losses ANSWER DOWNLOAD EXAMIANS APP
DC Motors The torque developed by a dc motor is directly proportional to None of the listed here Flux per pole × armature current Armature resistance × applied voltage Armature resistance × armature current None of the listed here Flux per pole × armature current Armature resistance × applied voltage Armature resistance × armature current ANSWER DOWNLOAD EXAMIANS APP
DC Motors Excessive motor vibration is caused by Bent shaft Too much brush tension Worn bearings Open armature coil Bent shaft Too much brush tension Worn bearings Open armature coil ANSWER DOWNLOAD EXAMIANS APP
DC Motors If conditions for maximum power for a dc motor are established, the efficiency of the motor will be 80 to 90 % 100 % Less than 50% 60 to 70 % 80 to 90 % 100 % Less than 50% 60 to 70 % ANSWER DOWNLOAD EXAMIANS APP
DC Motors During rheostat braking of dc series motor Motor is run at reduced speed None of the listed here Motor is reversed in direction Motor is run as a generator Motor is run at reduced speed None of the listed here Motor is reversed in direction Motor is run as a generator ANSWER DOWNLOAD EXAMIANS APP
DC Motors The main disadvantage of the Ward-Leonard control method is All of these High maintenance cost Low efficiency at high loads High initial cost All of these High maintenance cost Low efficiency at high loads High initial cost ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS