Electrical Machines In DC machine shape of armature MMF wave is? Triangular and directed towards main pole. Peaky in nature. Triangular and directed towards brush axis. Saddle shape. Triangular and directed towards main pole. Peaky in nature. Triangular and directed towards brush axis. Saddle shape. ANSWER DOWNLOAD EXAMIANS APP
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. 420 V. 400 V. 480 V. 350 V. 420 V. 400 V. 480 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Open circuit test on transformer gives eddy current loss hysteresis loss both 1and 2 copper loss eddy current loss hysteresis loss both 1and 2 copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if φ is the flux per pole and f is the frequency of the emf induced E then E ∝ 1/(φf) E ∝ φf E ∝ φ/f E ∝ f/φ E ∝ 1/(φf) E ∝ φf E ∝ φ/f E ∝ f/φ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What does the use the of height flux density value in transformer design lead to? Reduced copper loss. Increase in weight/KVA. Reduced iron loss. Decrease in weight/KVA. Reduced copper loss. Increase in weight/KVA. Reduced iron loss. Decrease in weight/KVA. ANSWER DOWNLOAD EXAMIANS APP