DC Motors In dc machines fractional pitch winding is used To reduce the generated emf To reduce the sparking To improve cooling To increase the generated emf To reduce the generated emf To reduce the sparking To improve cooling To increase the generated emf ANSWER DOWNLOAD EXAMIANS APP
DC Motors Carbon brushes are preferable to copper brushes because _____ They reduce sparking They have longer life They reduce armature reaction They have lower resistance They reduce sparking They have longer life They reduce armature reaction They have lower resistance ANSWER DOWNLOAD EXAMIANS APP
DC Motors In case the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be Less than 50% Anywhere between 75% and 90% Around 90% 1 Less than 50% Anywhere between 75% and 90% Around 90% 1 ANSWER DOWNLOAD EXAMIANS APP
DC Motors Small dc motors up to 5 HP usually have 6 poles 4 poles 2 poles 8 poles 6 poles 4 poles 2 poles 8 poles ANSWER DOWNLOAD EXAMIANS APP
DC Motors D.C. series motors are used None of these Where load is constant Where constant operating speed is needed Where load changes frequently None of these Where load is constant Where constant operating speed is needed Where load changes frequently ANSWER DOWNLOAD EXAMIANS APP
DC Motors Which D.C. motor is generally preferred for cranes and hoists? Series motor Cumulatively compounded motor Shunt motor Differentially compounded motor Series motor Cumulatively compounded motor Shunt motor Differentially compounded motor ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS