Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 5 / 6. 2 / 3. 4 / 5. 6 / 7. 5 / 6. 2 / 3. 4 / 5. 6 / 7. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by KhfBm. KhfBm3. KhfBm1.6. Khf2Bm1.6. KhfBm. KhfBm3. KhfBm1.6. Khf2Bm1.6. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% 82.5% 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 A 6 pole lap connected DC generator with 480 conductors has armature resistance of 0.06 Ω. If the conductors are reconnected to from a wave winding other things remaining unchanged, the value of armature resistance will be 0.06 Ω. 0.54 Ω. 0.54 Ω. 0.01 Ω. 0.06 Ω. 0.54 Ω. 0.54 Ω. 0.01 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound dc generator is delivering full load current at a terminal voltage of 230 V. Its series-field winding gets short circuited. If its terminal voltage 1. becomes more than 230 V, it is overcompounded generator 2. becomes more than 230 V, it is differentially compounded generator 3. becomes less than 230 V, it is overcompounded generator 4. becomes less than 230 V, it is differentially compounded generator 5. becomes less than 230 V, it is level compounded generator From these, the correct answer is 2,3 1, 4, 5 2, 3, 5 1, 4 2,3 1, 4, 5 2, 3, 5 1, 4 ANSWER DOWNLOAD EXAMIANS APP
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