Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 3/4. 16/9. 9/16. 4/3. 3/4. 16/9. 9/16. 4/3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are 1, 3, 4, 5 2, 3, 4, 5 2, 3, 4 1, 2, 3, 4 and 5 1, 3, 4, 5 2, 3, 4, 5 2, 3, 4 1, 2, 3, 4 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The principle of operation of a 3 - Φ induction motor is almost similar to that of capacitor start induction motor. synchronous motor. repulsion start induction motor. transformer with secondary short circuited. capacitor start induction motor. synchronous motor. repulsion start induction motor. transformer with secondary short circuited. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5Ω and back back emf 200 V is 440 A. 40 A. 44 A. 400 A. 440 A. 40 A. 44 A. 400 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 stack stepper motor has 12 teeth on stator as well as on rotor. Determine the step size when each stack excited? 45°. 24°. 30°. 10°. 45°. 24°. 30°. 10°. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS