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, 4, 5 2, 3, 4 2, 3 ,5 1, 2, 3 2, 3, 4, 5 2, 3, 4 2, 3 ,5 1, 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines We can apply source transformation to voltage source when a resistance is connected to it in 15 HP. 13 HP. 10 HP. 14 HP. 15 HP. 13 HP. 10 HP. 14 HP. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 3 to 5. 2 to 3. 1.0. 1.5 to 2. 3 to 5. 2 to 3. 1.0. 1.5 to 2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Motor is driving a constant load torque having armature resistance of 0.25 Ω and armature current of 60 A having connected to a voltage of 230 V. Now a resistance of 1 ohm is added into the armature circuit. The ratio of their speed will be 0.25. 1.24. 0.62. 0.72. 0.25. 1.24. 0.62. 0.72. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3000 rpm. 500 rpm. 600 rpm. 3600 rpm. 3000 rpm. 500 rpm. 600 rpm. 3600 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (1/2)Fmax. (3/2)Fmax. 3Fmax. Fmax. (1/2)Fmax. (3/2)Fmax. 3Fmax. Fmax. ANSWER DOWNLOAD EXAMIANS APP
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