DC Motors These days dc motors are widely used in Air compressors Electric traction Pumping sets Machine shops Air compressors Electric traction Pumping sets Machine shops 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% 1 Around 90% Less than 50% Anywhere between 75% and 90% 1 Around 90% ANSWER DOWNLOAD EXAMIANS APP
DC Motors In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to 10% of the previous value 50% of the previous value 25% of the previous value 100% of the previous value 10% of the previous value 50% of the previous value 25% of the previous value 100% of the previous value ANSWER DOWNLOAD EXAMIANS APP
DC Motors For a D.C. shunt motor if the excitation is changed Torque will change but power will remain constant Torque will remain constant Torque, power and speed, all will change Torque and power both will change Torque will change but power will remain constant Torque will remain constant Torque, power and speed, all will change Torque and power both will change ANSWER DOWNLOAD EXAMIANS APP
DC Motors The mechanical power developed by a shunt motor will be maximum when the ratio of back emf to applied voltage is 4.0 2.0 0.5 1.0 4.0 2.0 0.5 1.0 ANSWER DOWNLOAD EXAMIANS APP
DC Motors As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit A resistance is connected in series with armature Armature is temporarily open circuited A high value resistor is connected across the field winding A resistance is connected parallel to the armature A resistance is connected in series with armature Armature is temporarily open circuited A high value resistor is connected across the field winding A resistance is connected parallel to the armature ANSWER DOWNLOAD EXAMIANS APP
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