Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. over commutation. too rapid reversal of current. any of the above. under commutation. over commutation. too rapid reversal of current. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in dc machine provide ----------------- rectification? full wave controlled half wave full wave half wave controlled full wave controlled half wave full wave half wave controlled ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The emf induced in the dc generator armature winding is AC None of these AC and DC DC AC None of these AC and DC DC ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The volt-ampere euation for a long-shunt compound motor is given by Vt = Ea + Ia(ra + rs) Vt= Ea– Iara Vt= Ea + Iara Vt = Ea + Iara+ ILrs Vt = Ea + Ia(ra + rs) Vt= Ea– Iara Vt= Ea + Iara Vt = Ea + Iara+ ILrs ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to less than one. approx to one. greater than one. very low less than one. approx to one. greater than one. very low ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following DC generator will be in a position to build up without any residual magnetism in the field? Shunt. Separately excited. Compound. Series. Shunt. Separately excited. Compound. Series. ANSWER DOWNLOAD EXAMIANS APP