Electrical Machines The output voltage of a DC generator is E = V + IaRa. E = V – IaRa. E = V + Ra. E = V + Ia. E = V + IaRa. E = V – IaRa. E = V + Ra. E = V + Ia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 2.2 Ω 6 Ω 5.7 Ω 1.9 Ω 2.2 Ω 6 Ω 5.7 Ω 1.9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has synchronous speed of 1500 rpm. What will be the slip when it is running at a speed of 1450 rpm? +3.33% -3.33% -3% +3% +3.33% -3.33% -3% +3% 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%. 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eg (generated emf) and Eb (back emf) both are none of above. changes. different. same. none of above. changes. different. same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the cause of rapid brush wear may be severe sparking. imperfect contact. any of above. rough commutator surface. severe sparking. imperfect contact. any of above. rough commutator surface. ANSWER DOWNLOAD EXAMIANS APP
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