Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1000 1203 1080 1200 1000 1203 1080 1200 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On what factors the speed of dc motor depends? Armature current Ia. All of these. Applied voltage. Field flux. Armature current Ia. All of these. Applied voltage. Field flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 2 and 3 1 and 3 1 alone 1 and 2 2 and 3 1 and 3 1 alone 1 and 2 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 0.75 p.u 0.5 p.u 0.25 p.u 0.125 p.u 0.75 p.u 0.5 p.u 0.25 p.u 0.125 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor, the speed will____ if the voltage increases, neglecting armature saturation. be unpredictable. remain the same. decrease. increase be unpredictable. remain the same. decrease. increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slight curvature at the lower end of the OCC of a self excited DC generator is due to high speed. high field resistance. magnetic inertia. residual flux. high speed. high field resistance. magnetic inertia. residual flux. ANSWER DOWNLOAD EXAMIANS APP
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