Electrical Machines The commutator segments of DC machines are made up of brass copper alloy copper hard-drawn copper brass copper alloy copper hard-drawn copper ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature coil is short circuited by brushes when it lies in any of above positions. along neutral axis. in none of above positions. along field axis. in any of above positions. along neutral axis. in none of above positions. along field axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has negative speed regulation? Series motor Differential compound motor Cumulative compound motors Shunt motor Series motor Differential compound motor Cumulative compound motors Shunt motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 2 .1 Ω 1.8 9 Ω 1.79 Ω 3.1 Ω 2 .1 Ω 1.8 9 Ω 1.79 Ω 3.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be zero more than 6 V 6 V less than 6 V zero more than 6 V 6 V less than 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starter is not used with large DC motor for starting, it will damage the armature and commutator. all of above. provide execessive voltage drop in line. draw a starting current many times its rated full load current. damage the armature and commutator. all of above. provide execessive voltage drop in line. draw a starting current many times its rated full load current. ANSWER DOWNLOAD EXAMIANS APP
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