Electrical Machines For satisfactory performance of 3-phase 480V, 60 Hz induction motor, the supply voltage at 50 Hz should be equal to 350 V. 480 V. 420 V. 400 V. 350 V. 480 V. 420 V. 400 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In most condition which frame of motor will be preferred? Splash proof. Drip proof. Open type. Totally enclosed fan coiled. Splash proof. Drip proof. Open type. Totally enclosed fan coiled. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The stator core of a 3 - Φ induction motor is laminated in order to reduce the both of the above. hysteresis loss. weight of the stator. eddy current loss. both of the above. hysteresis loss. weight of the stator. eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor slots are slightly skewed in squirrel cage induction motor to provide ease of fabrication. reduce the magnetic hum and locking tendency of rotor. increase the strength of rotor bars. decrease the amount of copper to be used. provide ease of fabrication. reduce the magnetic hum and locking tendency of rotor. increase the strength of rotor bars. decrease the amount of copper to be used. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuit test is performed on a transformer with a certain impressed voltage at rated frequency. If the short circuit test is now performed with the same magnitude of impressed voltage, but at frequency higher than the rated frequency then The magnitude will both increase. The magnetude of current will increase, but power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnitude of circuit as well as the power factor will decrease. The magnitude will both increase. The magnetude of current will increase, but power factor will decrease. The magnitude of current will decrease but the power factor will increase. The magnitude of circuit as well as the power factor will decrease. ANSWER DOWNLOAD EXAMIANS APP
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