Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Decreases. Oscillates around the rated speed. Increases. Remains unchanged. Decreases. Oscillates around the rated speed. Increases. Remains unchanged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the actual flux distribution depends upon clearance between tips of the adjacent pole shoes. all of above. size of air gap. shape of the pole shoe. clearance between tips of the adjacent pole shoes. all of above. size of air gap. shape of the pole shoe. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 2, 3 and 4 3 and 5 1, 2 and 5 1 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is used in grinders? Split phase IM. Synchronous motor. Capacitor start IM. Capacitor start capacitor run IM. Split phase IM. Synchronous motor. Capacitor start IM. Capacitor start capacitor run IM. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where The speed in both the direction is required. All of above. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. The speed in both the direction is required. All of above. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. ANSWER DOWNLOAD EXAMIANS APP
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