Electrical Machines If the back emf in DC motor vanishes suddenly the motor will burn. run at very low speed. start haunting. run at very high speed. burn. run at very low speed. start haunting. run at very high speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor has synchronous speed of 1500 rpm. What will be the slip when it is running at a speed of 1450 rpm? +3.33% +3% -3.33% -3% +3.33% +3% -3.33% -3% 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, 3 and 5 1, 2 and 3 1 and 3 1, 2, 3 and 5 1, 3 and 5 1, 2 and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Alternator operates on the principle of self induction. electromagnetic induction. self or mutual induction. mutual induction. self induction. electromagnetic induction. self or mutual induction. mutual induction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC series motor the speed is ______________ proportional to the armature current. none of these. inversely. has no relation. directly. none of these. inversely. has no relation. directly. ANSWER DOWNLOAD EXAMIANS APP