Electrical Machines For high current and low current rating which winding is employed to DC machine? None of above Wave winding Lap winding Both lap and wave winding None of above Wave winding Lap winding Both lap and wave winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To get the speed of DC motor more than normal without wastage of electrical energy _____________ is used. rheostatic control. any of above method. none of above. Ward Leonard control. rheostatic control. any of above method. none of above. Ward Leonard control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3, 4, 5 2, 3, 4 1, 2, 3 2, 3 ,5 2, 3, 4, 5 2, 3, 4 1, 2, 3 2, 3 ,5 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 external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.1 Ω 15.9 Ω 31.1 Ω 31.9 Ω 15.1 Ω 15.9 Ω 31.1 Ω 31.9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An IM cannot run at synchronous speed because air friction will prevent it. induction motor will become synchronous motor. rotor torque will not be produced. none of above. air friction will prevent it. induction motor will become synchronous motor. rotor torque will not be produced. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 3 only 1, 2, 3 and 4 1, 2 and 3 1, 3 ANSWER DOWNLOAD EXAMIANS APP