Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will draw too much current. develop excessive speed and damage itself. open fuse or circuit breaker. produce sparking at brushes. draw too much current. develop excessive speed and damage itself. open fuse or circuit breaker. produce sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.25 p.u 0.75 p.u 0.5 p.u 0.125 p.u 0.25 p.u 0.75 p.u 0.5 p.u 0.125 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Around 100 %. Any where between 75 % and 90 %. Less than 50 % Around 90 % Around 100 %. Any where between 75 % and 90 %. Less than 50 % Around 90 % ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a cumulatively compound DC motor can be controlled by varying Shunt field resistance control. Armature voltage control. Armature resistance control. Any of above. Shunt field resistance control. Armature voltage control. Armature resistance control. Any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In speed control of DC Series motor, speed lower than the rated speed can be obtained by Any of the above. Connecting an additional resistance in the armature circuit. Connecting an additional resistance in the field circuit. Connecting an additional resistance in stator circuit. Any of the above. Connecting an additional resistance in the armature circuit. Connecting an additional resistance in the field circuit. Connecting an additional resistance in stator circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 3/4. 16/9. 4/3. 9/16. 3/4. 16/9. 4/3. 9/16. ANSWER DOWNLOAD EXAMIANS APP
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