Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to applied voltage. Back emf is equal to zero. None of above. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. Back emf is equal to zero. None of above. Back emf is equal to half the applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following speed control of DC motor the speed obtained is below than the rated speed? Armature voltage control. Field resistance control. Any of above. Armature circuit resistance control. Armature voltage control. Field resistance control. Any of above. Armature circuit resistance control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the mechanical power is developed by a DC motor maximum back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. Back emf is equal. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. Back emf is equal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For 250 volt DC Shunt Motor the armature and field resistance are 0.5 ohm and 250 ohm respectively. What will be the back e.m.f. produced when it takes a load current of 21A. 220 V. 150 V. 240 V. 280 V. 220 V. 150 V. 240 V. 280 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If terminal voltage of one 1000 rpm shunt motor is reduced to half the speed of the motor will be 500 rpm 1000 rpm 250 rpm 2000 rpm 500 rpm 1000 rpm 250 rpm 2000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf maximum ANSWER DOWNLOAD EXAMIANS APP
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