DC Motors D.C. generators are normally designed for maximum efficiency around Full load Rated voltage All of these Rated r.p.m. Full load Rated voltage All of these Rated r.p.m. ANSWER DOWNLOAD EXAMIANS APP
DC Motors The running speed of a dc series motor is basically determined by Load None of the listed here Field excitation Armature reaction Load None of the listed here Field excitation Armature reaction ANSWER DOWNLOAD EXAMIANS APP
DC Motors In D.C. machines the residual magnetism is of the order of 50 to 75 percent 20 to 25 percent 2 to 3 percent 10 to 15 percent 50 to 75 percent 20 to 25 percent 2 to 3 percent 10 to 15 percent ANSWER DOWNLOAD EXAMIANS APP
DC Motors If conditions for maximum power for a dc motor are established, the efficiency of the motor will be 100 % 80 to 90 % Less than 50% 60 to 70 % 100 % 80 to 90 % Less than 50% 60 to 70 % ANSWER DOWNLOAD EXAMIANS APP
DC Motors The back emf in a dc motor ______ Opposes the applied voltage Aids the applied voltage Aids the armature current None of the listed here Opposes the applied voltage Aids the applied voltage Aids the armature current None of the listed here 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 Armature is temporarily open circuited A high value resistor is connected across the field winding A resistance is connected in series with armature A resistance is connected parallel to the armature Armature is temporarily open circuited A high value resistor is connected across the field winding A resistance is connected in series with armature A resistance is connected parallel to the armature ANSWER DOWNLOAD EXAMIANS APP
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