Electrical Machines In DC generators brushes are used for collecting of voltage collecting of current without any sparkings reduce eddy current loss convert ac armature current in to dc collecting of voltage collecting of current without any sparkings reduce eddy current loss convert ac armature current in to dc ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when rate of change of flux is maximum. shaft rotation is high. induced voltage is high. rate of change of flux is minimum. rate of change of flux is maximum. shaft rotation is high. induced voltage is high. rate of change of flux is minimum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 88.8%. 48.0%. 57.1%. 59.2%. 88.8%. 48.0%. 57.1%. 59.2%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Increase. Reduce. Oscillate around the normal speed. Remain unaltered. Increase. Reduce. Oscillate around the normal speed. Remain unaltered. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is Fmax. (3/2)Fmax. (1/2)Fmax. 3Fmax. Fmax. (3/2)Fmax. (1/2)Fmax. 3Fmax. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers operating in parallel will share the load depending on their efficiency leakage reactance per unit impedance ratings efficiency leakage reactance per unit impedance ratings ANSWER DOWNLOAD EXAMIANS APP
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