DC Motors The direction of rotation of a D.C. series motor can be changed by Interchanging field terminals Interchanging supply terminals Either of (A) and (B) above None of these Interchanging field terminals Interchanging supply terminals Either of (A) and (B) above None of these 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 2.22% 6.77% 4.76% 8.85% 2.22% 6.77% 4.76% 8.85% ANSWER DOWNLOAD EXAMIANS APP
DC Motors The mechanical power developed in a dc motor is maximum when back emf is equal to _____ the applied voltage. Half None of the listed here One-third Twice Half None of the listed here One-third Twice ANSWER DOWNLOAD EXAMIANS APP
DC Motors If conditions for maximum power for a dc motor are established, the efficiency of the motor will be 60 to 70 % 80 to 90 % 100 % Less than 50% 60 to 70 % 80 to 90 % 100 % Less than 50% ANSWER DOWNLOAD EXAMIANS APP
DC Motors What will happen if the back emf of a dc motor vanishes suddenly? The motor will stop The motor will run noisy The armature may burn The motor will continue to run The motor will stop The motor will run noisy The armature may burn The motor will continue to run 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 and power both will change Torque will remain constant Torque, power and speed, all will change Torque will change but power will remain constant Torque and power both will change Torque will remain constant Torque, power and speed, all will change ANSWER DOWNLOAD EXAMIANS APP
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