Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 5 / 6. 6 / 7. 4 / 5. 2 / 3. 5 / 6. 6 / 7. 4 / 5. 2 / 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Remain unchanged. Increase by 5%. Reduce by 5%. Depends on other factor. Remain unchanged. Increase by 5%. Reduce by 5%. Depends on other factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 1.9 ohms. 6 ohms. 2.2 ohms. 5.7 ohms. 1.9 ohms. 6 ohms. 2.2 ohms. 5.7 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux is maximum in the following part of a DC motor: pole core. under leading pole tip. under trailing pole tip. under the interpole. pole core. under leading pole tip. under trailing pole tip. under the interpole. 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 and 3 1, 3 and 5 1 and 3 1, 2, 3 and 5 1, 2 and 3 1, 3 and 5 1 and 3 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When excitation is increased (over excitation), the synchronous generator operates at any of the above. lagging power factor. unity power factor. leading power factor. any of the above. lagging power factor. unity power factor. leading power factor. ANSWER DOWNLOAD EXAMIANS APP
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