Electrical Machines In DC machine shape of armature MMF wave is? Saddle shape. Peaky in nature. Triangular and directed towards main pole. Triangular and directed towards brush axis. Saddle shape. Peaky in nature. Triangular and directed towards main pole. Triangular and directed towards brush axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 30 W. 28 W. 36 W. 25 W. 30 W. 28 W. 36 W. 25 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 6 pole, 50 Hz IM is running at a full load speed of 980 rpm. If it delivers an air gap power of 98000 Watt, calculate the rotor ohmic loss? 1800 Watt. 1960 Watt. 1920 Watt. 980 Watt. 1800 Watt. 1960 Watt. 1920 Watt. 980 Watt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 V DC generator in run at rated speed with no excitation. The open circuit voltage will be zero. very small, say about 2 or 3 V. 250 V. about 100 V. zero. very small, say about 2 or 3 V. 250 V. about 100 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Poles of DC machine are often laminated to reduce armature reaction. reduce iron weight. dissipate more heat. reduce pulsation loss. reduce armature reaction. reduce iron weight. dissipate more heat. reduce pulsation loss. 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, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
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