DC Motors When the armature of a D.C. motor rotates, e.m.f. induced is Self-induced e.m.f. Mutually induced e.m.f. Back e.m.f. None of these Self-induced e.m.f. Mutually induced e.m.f. Back e.m.f. None of these ANSWER DOWNLOAD EXAMIANS APP
DC Motors If the speed of a dc shunt motor is increased the back emf of the motor will Decrease Become zero Increase Remains same Decrease Become zero Increase Remains same ANSWER DOWNLOAD EXAMIANS APP
DC Motors The direction of rotation of a D.C. series motor can be changed by Either of (A) and (B) above Interchanging field terminals None of these Interchanging supply terminals Either of (A) and (B) above Interchanging field terminals None of these Interchanging supply terminals 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 Around 90% 1 Less than 50% Anywhere between 75% and 90% Around 90% 1 Less than 50% Anywhere between 75% and 90% ANSWER DOWNLOAD EXAMIANS APP
DC Motors The speed of a dc motor is inversely proportional to flux per pole Directly proportional to flux per pole inversely proportional to applied voltage None of the listed here inversely proportional to flux per pole Directly proportional to flux per pole inversely proportional to applied voltage 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