Electrical Machines The output voltage of a DC generator is E = V + IaRa. E = V + Ia. E = V + Ra. E = V – IaRa. E = V + IaRa. E = V + Ia. E = V + Ra. E = V – IaRa. 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 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 2, 3 and 4 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere. None of these. 120 volt. 218.5 volt. 220.4 volt. None of these. 120 volt. 218.5 volt. 220.4 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a part of transformer? Conservator tank. Tap changer. Radiator. Commutator. Conservator tank. Tap changer. Radiator. Commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine shape of armature MMF wave is? Saddle shape. Peaky in nature. Triangular and directed towards brush axis. Triangular and directed towards main pole. Saddle shape. Peaky in nature. Triangular and directed towards brush axis. Triangular and directed towards main pole. 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 : 1 and 3 1, 2, and 3 1, 2 and 4 2, 3 and 4 1 and 3 1, 2, and 3 1, 2 and 4 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
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