Electrical Machines The material used for commutator brushes is mostly copper. carbon. mica. cast iron. copper. carbon. mica. cast iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be either (B) or (C). equal to number of rotor slots. unequal to number of rotor slots and skewed in shape. an integral multiple of number of rotor slots. either (B) or (C). equal to number of rotor slots. unequal to number of rotor slots and skewed in shape. an integral multiple of number of rotor slots. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of squirrel cage induction motor is both A and B low at heavy loads only low at rated load only low at light loads only both A and B low at heavy loads only low at rated load only low at light loads only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm? 5 24 10 12 5 24 10 12 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines It is advisable to start a DC series motor with some load to Limit the current. Limit the speed. Limit the flux. Avoid sparking. Limit the current. Limit the speed. Limit the flux. Avoid sparking. ANSWER DOWNLOAD EXAMIANS APP
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