Electrical Machines A cumulatively compounded dc motor delivers rated load power at rated speed. If the series field is short-circuited, then Ia remains constant but ωm increase Ia increases and ωm decreses both armature current Ia and speed ωm increase both decrese Ia remains constant but ωm increase Ia increases and ωm decreses both armature current Ia and speed ωm increase both decrese ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will produce sparking at brushes. open fuse or circuit breaker. draw too much current. develop excessive speed and damage itself. produce sparking at brushes. open fuse or circuit breaker. draw too much current. develop excessive speed and damage itself. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The 3 - Φ induction motor with rotor circuit open will run normally. not run. get over heated. make noise. run normally. not run. get over heated. make noise. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor electromotive force of the IM is observed to make 100 complete alterations per minute, calculated slip 3.33 %. 0 .001 %. 3 %. None of these 3.33 %. 0 .001 %. 3 %. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, the demagnetizing effect of armature reaction is due to uneven air-gap length magnetic saturation in half of the field pole non-sinusoidal nature of armature mmf component of armature mmf along field axis uneven air-gap length magnetic saturation in half of the field pole non-sinusoidal nature of armature mmf component of armature mmf along field axis ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a 3 - Φ induction motor is clockwise when it is supplied with 3 - Φ sinusoidal voltage having phase sequence A - B - C. For counterclockwise rotation of motor, the phase sequence of the supply should be C - A - B. A - C - B. B - C - A or C - A - B. B - C - A. C - A - B. A - C - B. B - C - A or C - A - B. B - C - A. ANSWER DOWNLOAD EXAMIANS APP
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