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 2.2 Ω 6 Ω 1.9 Ω 5.7 Ω 2.2 Ω 6 Ω 1.9 Ω 5.7 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging and crawling are phenomena associated with the former during starting and the latter at a fraction of its rated speed. any of the above. the former at a fraction of its rate speed and the latter during starting. cage induction machines and they are essentially the same. the former during starting and the latter at a fraction of its rated speed. any of the above. the former at a fraction of its rate speed and the latter during starting. cage induction machines and they are essentially the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting in a synchronous motor takes place motor is under loaded. when power factor is unity. when load varies. when supply voltage fluctuates. motor is under loaded. when power factor is unity. when load varies. when supply voltage fluctuates. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of rotor resistance. Change of supply voltage. Change of supply frequency. Change of number of pole. Change of rotor resistance. Change of supply voltage. Change of supply frequency. Change of number of pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the synchronous reactance of alternators in which a given field current of 200 A on short circuit and a generated emf of 50 V on open circuit. Armature resistance is 0.1 ohm 0.5Ω. 0.25Ω. 1Ω. 0.23Ω. 0.5Ω. 0.25Ω. 1Ω. 0.23Ω. ANSWER DOWNLOAD EXAMIANS APP
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