Electrical Machines When the supply terminal of a DC shunt motor are interchanged The motor will stop. The motor will run much faster in the same direction. The motor will run at its normal speed in the same direction as before. The direction of rotation will reverse. The motor will stop. The motor will run much faster in the same direction. The motor will run at its normal speed in the same direction as before. The direction of rotation will reverse. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the motor may not start. the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. the motor may run away. the starting torque becomes low. the starting current will be enormously high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a synchronous motor is running at synchronous speed, the damper winding produces both 1 and 2. no torque. eddy current torque. damping torqe. both 1 and 2. no torque. eddy current torque. damping torqe. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 2, 3, 6 1, 2, 5 2, 4, 5, 6 3, 4, 5 2, 3, 6 1, 2, 5 2, 4, 5, 6 3, 4, 5 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 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines, the interpoles are provided to make commutation spark less. both (B) and (C). to counteract the reactance voltage and the cross-magnetizi to counteract demagnetizing effect of armature mmf in commutating zone. to make commutation spark less. both (B) and (C). to counteract the reactance voltage and the cross-magnetizi to counteract demagnetizing effect of armature mmf in commutating zone. ANSWER DOWNLOAD EXAMIANS APP
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