Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is Fmax. (1/2)Fmax. 3Fmax. (3/2)Fmax. Fmax. (1/2)Fmax. 3Fmax. (3/2)Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when induced voltage is high. rate of change of flux is maximum. rate of change of flux is minimum. shaft rotation is high. induced voltage is high. rate of change of flux is maximum. rate of change of flux is minimum. shaft rotation is high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 40 A. 440 A. 400 A. 44 A. 40 A. 440 A. 400 A. 44 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will run at very low speed. burn. start haunting. run at very high speed. run at very low speed. burn. start haunting. run at very high speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to any of above. failure of insulation between two turns of coil. failure of insulation between two commutator bars. grounding of two or more turns of the same coil. any of above. failure of insulation between two turns of coil. failure of insulation between two commutator bars. grounding of two or more turns of the same coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine is invariably provided with forced ventilation? Fractional horse power high speed motor. Fractional horse power slow speed motor. 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. Fractional horse power slow speed motor. 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. ANSWER DOWNLOAD EXAMIANS APP
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