Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.45 Ω. 0.66 Ω. 0.24 Ω. 0.78 Ω. 0.45 Ω. 0.66 Ω. 0.24 Ω. 0.78 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, the armature reaction results in magnetization of inter poles. magnetization of leading and demagnetization of trailing pole tip. demagnetization of leading & magnetization of trailing pole tip. demagnetization of centers of poles. magnetization of inter poles. magnetization of leading and demagnetization of trailing pole tip. demagnetization of leading & magnetization of trailing pole tip. demagnetization of centers of poles. 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 2, 3, 4 1, 2, 5 1, 3, 5 1, 2, 3, 4 2, 3, 4 1, 2, 5 1, 3, 5 1, 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 3.05+j5.08 ohms 3.5+j5.8 ohms 53+j85 ohms 8+j13 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 53+j85 ohms 8+j13 ohms ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For very sensitive and wide speed control, the preferable control method is Field control. Armature control. Multiple voltage control. Ward-Leonard control. Field control. Armature control. Multiple voltage control. Ward-Leonard control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings is placed in which part of a D.C motor? On yoke in the inter pole gap. On yoke in the pole faces. None of these On armature. On yoke in the inter pole gap. On yoke in the pole faces. None of these On armature. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS