Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 1 at 90°C. 2 at 90°C. 3 at 90°C. 0.5 at 90°C. 1 at 90°C. 2 at 90°C. 3 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Interpoles in a DC motor must be Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will draw too much current. open fuse or circuit breaker. produce sparking at brushes. develop excessive speed and damage itself. draw too much current. open fuse or circuit breaker. produce sparking at brushes. develop excessive speed and damage itself. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Dissolve gas analysis of transformer oil is carried out to determine condition of bushings. condition of transformer oil. condition of bushing stud. condition of transformer. condition of bushings. condition of transformer oil. condition of bushing stud. condition of transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines shape of net flux density is? saddle shape flat tapped or trapezoidal peaky in nature sine wave saddle shape flat tapped or trapezoidal peaky in nature sine wave ANSWER DOWNLOAD EXAMIANS APP
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 Remains unchanged. Oscillates around the rated speed. Increases. Decreases. Remains unchanged. Oscillates around the rated speed. Increases. Decreases. ANSWER DOWNLOAD EXAMIANS APP