Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will deteriorate with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with fall of terminal voltage. improve with rise in terminal voltage. deteriorate with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with fall of terminal voltage. improve with rise in terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to external star-connected resistors. equalizing coils. DC supply. 3 - Φ AC supply. external star-connected resistors. equalizing coils. DC supply. 3 - Φ AC supply. ANSWER DOWNLOAD EXAMIANS APP
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 decrese both armature current Ia and speed ωm increase Ia remains constant but ωm increase Ia increases and ωm decreses both decrese both armature current Ia and speed ωm increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 2, 3 1, 4 1, 3 2, 4 2, 3 1, 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The material used for commutator brushes is mostly carbon. cast iron. copper. mica. carbon. cast iron. copper. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip speed is the sum of synchronous and rotor speeds. difference of actual rotor speed and synchronous speed. half of the sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. sum of synchronous and rotor speeds. difference of actual rotor speed and synchronous speed. half of the sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. ANSWER DOWNLOAD EXAMIANS APP
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