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 What will happen if the the supply terminals are reversed in case of a DC shunt motor? The motor will run in reverse direction. The motor will run at its normal speed in the same direction as before. The motor will stop. The motor will run much faster in the same direction. The motor will run in reverse direction. The motor will run at its normal speed in the same direction as before. The motor will stop. The motor will run much faster in the same direction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Magnetic field of a DC generator is produced by what? None of the options. Both B and C. Permanent magnets. Electromagnets. None of the options. Both B and C. Permanent magnets. Electromagnets. 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 1 alone 1 and 3 1 and 2 2 and 3 1 alone 1 and 3 1 and 2 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In speed control of DC shunt motor by varying field flux, what may be the value of field regulator? 10 ohm 100 ohm 2 ohm. 0.2 ohm 10 ohm 100 ohm 2 ohm. 0.2 ohm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single phase transformer has specifications as 250 KVA, 11000 V/415 V, 50 Hz. What are the values of primary and secondary currents? primary = 602 A, secondary = 22.7 A primary = 11.4 A, secondary = 301 A primary = 22.7 A, secondary = 602.4 A primary = 301 A, secondary = 22.7 A primary = 602 A, secondary = 22.7 A primary = 11.4 A, secondary = 301 A primary = 22.7 A, secondary = 602.4 A primary = 301 A, secondary = 22.7 A ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS