Electrical Machines Conservator tank is used to act as an oil storage. to take up the expansion of oil due to temperature rise. None of these for better cooling of transformer. to act as an oil storage. to take up the expansion of oil due to temperature rise. None of these for better cooling of transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC motor is laminated to reduce the inductor. to reduce the mass. to reduce the hysteresis loss. to reduce the eddy current loss. to reduce the inductor. to reduce the mass. to reduce the hysteresis loss. to reduce the eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2, 3 and 5 1 and 3 1, 2 and 3 1, 3 and 5 1, 2, 3 and 5 1 and 3 1, 2 and 3 1, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 88.8%. 57.1%. 59.2%. 48.0%. 88.8%. 57.1%. 59.2%. 48.0%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, the angle between the stator and rotor fields is 0o. 90o. dependent upon the load. 180o. 0o. 90o. dependent upon the load. 180o. 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 0.125 p.u 0.5 p.u 0.25 p.u 0.75 p.u 0.125 p.u 0.5 p.u 0.25 p.u 0.75 p.u ANSWER DOWNLOAD EXAMIANS APP