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, I/2 and P/2 V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 V/2, I and P/2 V/2, I/2 and P/4 V, I and P ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If iron loss and full load copper loss of any transformer are denoted by Pi and Pc, then the load corresponding to maximum efficiency is given by (Pi / Pc) × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc)2 × full Load. (Pi / Pc) × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc)2 × full Load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In star-delta starting of squirrel cage induction motor compared to DOL starting the starting current and torque are 1/√3, 1/√3 1/√3, 1/3 1/3, 1/3 1/3, 1/√3 1/√3, 1/√3 1/√3, 1/3 1/3, 1/3 1/3, 1/√3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 36.36% decrease 18.18% increase 36.36% increase 36.36% increase 36.36% decrease 18.18% increase 36.36% increase 36.36% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1, 2 and 3 1 and 2 2 alone 1 and 3 1, 2 and 3 1 and 2 2 alone 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Damper winding is used to suppress the hunting. increase the load current. both 1 and 2. decrease the load current. suppress the hunting. increase the load current. both 1 and 2. decrease the load current. ANSWER DOWNLOAD EXAMIANS APP
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