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, 3 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. None of these. Heavy sparking at brushes. Both of above. Heavy sparking at the first stud of starting resistance steps. None of these. Heavy sparking at brushes. Both of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a synchronous motor is running at synchronous speed, the damper winding produces eddy current torque. both 1 and 2. damping torqe. no torque. eddy current torque. both 1 and 2. damping torqe. no torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In auto transformer if the turn ratio is K, what is the power transferred inductively? (1-K) × input power K × input power both A and B None of these (1-K) × input power K × input power both A and B None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Ke is eddy current constant, Kf is form factor, f is supply frequency, Bm maximum flux density in core of transformer, the expression of eddy current loss in transformer, is given by Kef2Kf2Bm. Kef2Kf2Bm2. Kef2KfBm2. KefKf2Bm2. Kef2Kf2Bm. Kef2Kf2Bm2. Kef2KfBm2. KefKf2Bm2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine 72 number of coils are used. Find the number of commutator segments required? 72 74 36 37 72 74 36 37 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS