Electrical Machines If the excitation is critical, the power factor of the alternator is lagging power factor. leading power factor. None of these unity power factor. lagging power factor. leading power factor. None of these unity power factor. 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 2, 3, 4, 5 1, 3, 4, 5 1, 2, 3, 4 and 5 2, 3, 4 2, 3, 4, 5 1, 3, 4, 5 1, 2, 3, 4 and 5 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slot edges in a DC machine are made of Silicon steel. Fibre. Cast iron. Mild steel. Silicon steel. Fibre. Cast iron. Mild steel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following DC Motor the ratio of starting torque to full load torque is minimum? Differential compound motor. Cumulative compound motor. Series motor. Shunt motor. Differential compound motor. Cumulative compound motor. Series motor. Shunt motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a DC series motor is Inversely proportional to the armature current. Proportional to field current. Proportional to the square of the armature current. Proportional to the armature current. Inversely proportional to the armature current. Proportional to field current. Proportional to the square of the armature current. Proportional to the armature current. ANSWER DOWNLOAD EXAMIANS APP
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