Electrical Machines A 4 pole lap wound dc generator has 4 brushes, if one of the brush is damaged, what will be the change in V, I and P ratings V/2, I/2 and P/4 V/2, I and P/2 V, I/2 and P/2 V, I and P V/2, I/2 and P/4 V/2, I and P/2 V, I/2 and P/2 V, I and P ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the reactance voltage when current is changed from -2A to 2A in 4 sec and self inductance is 1H? 1 V 2 V 0 V 4 V 1 V 2 V 0 V 4 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increases in field excitation of a DC generator, its generated emf remains constant. decreases. increases. increases upto a limit and then remains almost constant. remains constant. decreases. increases. increases upto a limit and then remains almost constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Semi closed slots or totally closed slots are used in induction motors, essentially to decrease starting torque reduce magnetising current and improve power factor increase pull out torque improve starting torque decrease starting torque reduce magnetising current and improve power factor increase pull out torque improve starting torque ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited dc motor has an armature resistance of 0.5 Ω. It runs off a 250 V dc supply Drawing an armature current of 20 A at 1500 rpm. The torque developed for an armature current Of 10 A, for the same field current, will be 15.6 Nm 15.92 Nm 15.28 Nm 16.55 Nm 15.6 Nm 15.92 Nm 15.28 Nm 16.55 Nm ANSWER DOWNLOAD EXAMIANS APP
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