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 0.23Ω. 1Ω. 0.25Ω. 0.5Ω. 0.23Ω. 1Ω. 0.25Ω. 0.5Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 1, 2 and 5 1 and 4 3 and 5 2, 3 and 4 1, 2 and 5 1 and 4 3 and 5 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the reactance voltage when current is changed from -2A to 2A in 4 sec and self inductance is 1H? 1 V 0 V 4 V 2 V 1 V 0 V 4 V 2 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will becomes four times. It will remain the same. It will be doubled. It will be halved. It will becomes four times. It will remain the same. It will be doubled. It will be halved. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 115 V 230 V 460 V 200 V 115 V 230 V 460 V 200 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is Pc/Pi (Pi/Pc)2 Pi/Pc √(Pi/Pc) Pc/Pi (Pi/Pc)2 Pi/Pc √(Pi/Pc) ANSWER DOWNLOAD EXAMIANS APP
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