Scott connection is used for A 3-phase to 2-phase conversion B to achieve higher effciency C to save copper D to reduce harmonics

2315

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Calculate torque developed by the 3-phase, 5 H.P., 4 pole induction motor runs at 1500 rpm A 23 N-m B 21 N-m C 10 N-m D 0 N-m

5211

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The slip during plugging operation is given by= A 1-s B 2+s C 1+s D 2-s

2845

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During regenerative breaking= A rotating magnetic field is reversed B slip is positive C torque is positive D slip is negative

2134

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In which of the following case, the rotating magnetic field is reversed? A regenerative breaking B plugging C dynamic breaking D forward motoring

1978

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Electromagnetic torque developed by the motor is compared to shaft torque. A less B same C depends on motor design D more

2040

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An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The rotor reactance at stand still is A 2 ohm B 1.25 ohm C 3.15 ohm D 2.25 ohm

2288

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An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The slip when motor stalls is A 1 B 0 C 13.33% D 10.33%

1937

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Transformer cores are laminated in order to A simplify its construction B minimize eddy current loss C reduce cost D reduce hysterisis loss

3281

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Saving in copper achieved by converting a 2 winding transformer in to an auto transformer is determined by A voltage transformation ratio B load on secondary C quality of core material D size of transformer core

3152

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kVA rating of ordinary transformer is increased when connected as an auto transformer because A transformation ratio increased B secondary voltage increased C energy is transferred both inductively and conductively D secondary current increased

2665

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Following test should be conducted to find out relative polarity of transformenr terminals A no load test B back to back test C phasing out test D none of above

2225

---

Main advantage of auto transformer over two windings transformer is that A it needs no cooling B it uses only one winding C core losses are reduced D it has simple construction

2954

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what is difference between server 2008R1 and 2008 server R2?

1804

---

If we impress a dc voltage of 230 V on an unloaded 230 V, 50 Hz transformer it wi A give high secondary voltage B burn out C give secondary voltage as per K D none of these

2006

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