Electrical Machines A commutator in dc machine provide ----------------- rectification? half wave full wave half wave controlled full wave controlled half wave full wave half wave controlled full wave controlled ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starting current of a 3 - Φ induction motor is 5 times the rated current, while rated slip is 4 %, then ratio of starting torque to full load torque is 1. 0.8. 0.4. 0.6. 1. 0.8. 0.4. 0.6. 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, 2, 3, 4 and 5 2, 3, 4, 5 2, 3, 4 1, 3, 4, 5 1, 2, 3, 4 and 5 2, 3, 4, 5 2, 3, 4 1, 3, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To get the speed of DC motor is more than normal without wastage of electrical energy _____________ is used. Any of above method. None of above. Ward Leonard control. Rheostatic control. Any of above method. None of above. Ward Leonard control. Rheostatic control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Speed of DC motor can be controlled by varying its flux oer pole. resistance of armature culture. all of these. applied voltage. its flux oer pole. resistance of armature culture. all of these. applied voltage. 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