Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 1, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft of induction motor may be unbalanced due to uneven air gap. poor lubrication. overheating of winding. overload. uneven air gap. poor lubrication. overheating of winding. overload. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer cooling and insulating oil must be of low viscosity. high viscosity. low BDV. low resistivity. low viscosity. high viscosity. low BDV. low resistivity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On switching a DC motor to DC supply mains, it is found to rotate in the direction opposite to that for which it is designed. The DC motor is Differentical compound. have an equal number of electrons and protons. Cummulative compound. Series shunt. Differentical compound. have an equal number of electrons and protons. Cummulative compound. Series shunt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net voltage across the armature resistance at the time of plugging will be 234 V 474 V 240 V 6 V 234 V 474 V 240 V 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers with identical rating, are designed with flux densities of 1.2 and 1.4 Wb / m2 respectively. The weight of first transformer per kVA is more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. ANSWER DOWNLOAD EXAMIANS APP
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