Electrical Machines The output voltage of a DC generator is E = V + IaRa. E = V – IaRa. E = V + Ia. E = V + Ra. E = V + IaRa. E = V – IaRa. E = V + Ia. E = V + Ra. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is between 50% and 90%. less than 50%. same. more. between 50% and 90%. less than 50%. same. more. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions is a dc motor provided with compensating winding used ? 1. Wide range of speed control above normal 2. Wide range of steady load variation with no speed control 3.Wide range of rapid variation in load Select the correct answer using the codes given below : Codes : 1 and 2 1, 2 and 3 1 and 3 2 and 3 1 and 2 1, 2 and 3 1 and 3 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA 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 speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 970 RPM 960 RPM 920 RPM 940 RPM 970 RPM 960 RPM 920 RPM 940 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. restoring torque. damping torque. mechanical rotatory system. synchronizing power co efficient. restoring torque. damping torque. mechanical rotatory system. synchronizing power co efficient. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation of the synchronous generator fails, it acts as a/an synchronous generator. synchronous motor. induction motor. induction generator. synchronous generator. synchronous motor. induction motor. induction generator. ANSWER DOWNLOAD EXAMIANS APP
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