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. Depends on other factor. Reduce by 5%. Increase by 5%. Remain unchanged. Depends on other factor. Reduce by 5%. Increase by 5%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is 50 V 20 V zero 40 V 50 V 20 V zero 40 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is Pc/Pi (Pi/Pc)2 √(Pi/Pc) Pi/Pc Pc/Pi (Pi/Pc)2 √(Pi/Pc) Pi/Pc ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop DC motor torque. induction motor torque. induction generator torque. synchronous motor torque. DC motor torque. induction motor torque. induction generator torque. synchronous motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.95 0.96 0.87 1.06 0.95 0.96 0.87 1.06 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Motors for fans and pumps are selected in the rpm range 375 to 500. 1440 to 2880. 500 to 720. 720 to 920. 375 to 500. 1440 to 2880. 500 to 720. 720 to 920. ANSWER DOWNLOAD EXAMIANS APP
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