Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Lagging power factor. Zero power factor. Leading power factor. Unity power factor. Lagging power factor. Zero power factor. Leading power factor. Unity power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2 and 3 1, 2, 3 and 5 1, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 1, 3 and 5 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
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 5.7 Ω 1.9 Ω 2.2 Ω 6 Ω 5.7 Ω 1.9 Ω 2.2 Ω 6 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Oscillates around the rated speed. Decreases. Remains unchanged. Increases. Oscillates around the rated speed. Decreases. Remains unchanged. Increases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 2 pole, 12 slot synchronous machine is operating at synchronous speed. Find the slot angle? 60° 20° 30° 18° 60° 20° 30° 18° ANSWER DOWNLOAD EXAMIANS APP
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. 4 / 5. 2 / 3. 6 / 7. 5 / 6. 4 / 5. 2 / 3. 6 / 7. ANSWER DOWNLOAD EXAMIANS APP
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