Electrical Machines In DC generators, the cause of rapid brush wear may be rough commutator surface. severe sparking. imperfect contact. any of above. rough commutator surface. severe sparking. imperfect contact. any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When flux density is constant in a transformer, hysteresis loss varies as V² f² V f V² f² V f ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor of a three phase induction motor has an impedance of 0.4 + j4 ohm per phase at standstill the maximum torque occurs at a slip of _____________. 15 %. 50 %. 25 %. 10 %. 15 %. 50 %. 25 %. 10 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 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. 1 at 90°C. 2 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is power factor of a 3 - φ induction motor at no load? Equal to 1. Low. High. Same as full load. Equal to 1. Low. High. Same as full load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor of a 3 - Φ wound induction motor is provided with heavy copper or aluminium bars placed in rotor slots. single phase winding. three phase winding. heavy short-circuited end rings. heavy copper or aluminium bars placed in rotor slots. single phase winding. three phase winding. heavy short-circuited end rings. ANSWER DOWNLOAD EXAMIANS APP
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