Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3 ,5 2, 3, 4 2, 3, 4, 5 1, 2, 3 2, 3 ,5 2, 3, 4 2, 3, 4, 5 1, 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the space distribution of air-gap flux density wave at no load is co- sinusoidal sinusoidal rectangular flat-topped co- sinusoidal sinusoidal rectangular flat-topped ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. None of these. Heavy sparking at the first stud of starting resistance steps. Both of above. Heavy sparking at brushes. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer, hysteresis and eddy current losses depend upon load current maximum flux density supply frequency both 2 and 3 load current maximum flux density supply frequency both 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two windings provided on the stator of 1-phase induction motor, one main winding and the other auxiliary winding are connected either of these depending on the design of the motor in series in parallel through inductive coupling either of these depending on the design of the motor in series in parallel through inductive coupling 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+ ILrs Vt= Ea + Iara Vt= Ea– Iara Vt = Ea + Ia(ra + rs) Vt = Ea + Iara+ ILrs Vt= Ea + Iara Vt= Ea– Iara ANSWER DOWNLOAD EXAMIANS APP