Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 6 Ω 5.7 Ω 1.9 Ω 2.2 Ω 6 Ω 5.7 Ω 1.9 Ω 2.2 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the armature windings are placed on the rotor because of the necessity for development of torque commutation generation of voltage electromechanical energy conversion development of torque commutation generation of voltage electromechanical energy conversion ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to any of above. failure of insulation between two turns of coil. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. any of above. failure of insulation between two turns of coil. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For successful parallel operation of two single phase transformers, the most essential condition is that their percentage impedances are equal polarities are properly connected KVA ratings are equal turn- ratios are exactly equal percentage impedances are equal polarities are properly connected KVA ratings are equal turn- ratios are exactly equal ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator pitches of duplex and simplex lap windings are respectively 2 and 1 4 ang 1 4 and 2 2 and 2 2 and 1 4 ang 1 4 and 2 2 and 2 ANSWER DOWNLOAD EXAMIANS APP
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