Electrical Machines Motors for fans and pumps are selected in the rpm range 720 to 920. 500 to 720. 375 to 500. 1440 to 2880. 720 to 920. 500 to 720. 375 to 500. 1440 to 2880. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator if field winding attains the critical resistance machine will generate maximum voltage. machine will generate maximum power. the voltage generated will be zero. field winding will burn. machine will generate maximum voltage. machine will generate maximum power. the voltage generated will be zero. field winding will burn. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 2, 4, 5, 6 3, 4, 5 2, 3, 6 1, 2, 5 2, 4, 5, 6 3, 4, 5 2, 3, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The damper windings also called the squirrel cage windings or damper grids are provided in a synchronous motor to make it self starting. consists of short-circuited copper bars embedded in the field pole faces. are provided on the stator for improving power factor. both (A) and (B). are provided in a synchronous motor to make it self starting. consists of short-circuited copper bars embedded in the field pole faces. are provided on the stator for improving power factor. both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip exists in in both machines. none of above. induction motor. synchronous motor. in both machines. none of above. induction motor. synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods are used to control the speed of DC motors is supply voltage control field current control armature circuit resistance control All of these supply voltage control field current control armature circuit resistance control All of these ANSWER DOWNLOAD EXAMIANS APP
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