Electrical Machines The armature resistance of the dc motor is generally of the range 100 ohm. 0.5 ohm. 50 ohm. 0.1 ohm. 100 ohm. 0.5 ohm. 50 ohm. 0.1 ohm. ANSWER DOWNLOAD EXAMIANS APP
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 1, 2, 3 2, 3, 4 2, 3, 4, 5 2, 3 ,5 1, 2, 3 2, 3, 4 2, 3, 4, 5 2, 3 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which DC motor will have least percentage increase of input current, for the same percentage increase in the torque Separately Excited DC Motor DC Shunt Motor DC Series Motor Compound Wound DC Motor Separately Excited DC Motor DC Shunt Motor DC Series Motor Compound Wound DC Motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1/2. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Tap changer is generally provided in voltage transformer. current transformer. power transformer. earthing transformer. voltage transformer. current transformer. power transformer. earthing transformer. ANSWER DOWNLOAD EXAMIANS APP
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