Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.2. 1.8. 1.5. 1.4. 1.2. 1.8. 1.5. 1.4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following, voltage regulation may be zero or negative lagging power factor unity power factor leading power factor All of these lagging power factor unity power factor leading power factor All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 4. 7. 3. 12. 4. 7. 3. 12. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum power developed by a synchronous motor depends on supply voltage and load angle supply voltage and excitation supply voltage, load angle and excitation excitation and load angle supply voltage and load angle supply voltage and excitation supply voltage, load angle and excitation excitation and load angle ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The polarity of a DC generator can be reversed by any of above. reversing the field current. increasing field current. reversing field electric current as well as direction of rotation. any of above. reversing the field current. increasing field current. reversing field electric current as well as direction of rotation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 67.5% 72.5% 82.5% 78.5% 67.5% 72.5% 82.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
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