Electrical Machines The armature core of the rotor bars of dc motors are laminated to provide better flux linkage. to reduce hysteresis loss. to reduce mechanical losses. to reduce eddy current loss. to provide better flux linkage. to reduce hysteresis loss. to reduce mechanical losses. to reduce eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 2 pole lap winding dc machine , the resistance of one conductor is 2Ω and total number of conductors is 100. Find the total resistance 200Ω 100Ω 50Ω 10Ω 200Ω 100Ω 50Ω 10Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Oscillates around the rated speed. Decreases. Remains unchanged. Increases. Oscillates around the rated speed. Decreases. Remains unchanged. Increases. 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, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 1, 3 and 5 1 and 3 1, 2 and 3 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 18. 36. 50. 80. 18. 36. 50. 80. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net voltage across the armature resistance at the time of plugging will be 474 V 6 V 234 V 240 V 474 V 6 V 234 V 240 V ANSWER DOWNLOAD EXAMIANS APP
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