DC Motors In D.C. machines the residual magnetism is of the order of 20 to 25 percent 50 to 75 percent 2 to 3 percent 10 to 15 percent 20 to 25 percent 50 to 75 percent 2 to 3 percent 10 to 15 percent ANSWER DOWNLOAD EXAMIANS APP
DC Motors The shaft torque in a dc motor is less than total armature torque because of ______ in the motor. None of the listed here Field losses Cu losses Iron and friction losses None of the listed here Field losses Cu losses Iron and friction losses ANSWER DOWNLOAD EXAMIANS APP
DC Motors In a dc motor, the brushes are shifted from the mechanical neutral plane in a direction opposite to the rotation to _____ Increase speed Reduce sparking Produce flat characteristics Decrease speed Increase speed Reduce sparking Produce flat characteristics Decrease speed ANSWER DOWNLOAD EXAMIANS APP
DC Motors The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is 6.77% 8.85% 4.76% 2.22% 6.77% 8.85% 4.76% 2.22% ANSWER DOWNLOAD EXAMIANS APP
DC Motors A series motor will over speed when The armature circuit is opened. Load is removed The load is increase The field is opened The armature circuit is opened. Load is removed The load is increase The field is opened ANSWER DOWNLOAD EXAMIANS APP
DC Motors Carbon brushes are preferable to copper brushes because _____ They reduce sparking They reduce armature reaction They have longer life They have lower resistance They reduce sparking They reduce armature reaction They have longer life They have lower resistance ANSWER DOWNLOAD EXAMIANS APP
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