Why We Can’t Store AC Voltages ?

Why we can not store AC like DC Before going to discussion on "why we can't store ac current in batteries" understand what is AC & DC voltages.AC voltage changes it's polarity 50-60 times per second (50Hz for India,UK & 60Hz for USA).But DC is constant voltage with respect to time.If we consider charging mechanism of electro-chemical cell or battery,it is continuous process of injecting electrons on negative...

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Brake Test on DC Shunt Motor:Efficiency By Direct Loading

In this method, the d.c. machine is loaded and output and input are measured to find the efficiency. For this purpose, two simple methods can be used. Brake test on dc machine:- In this method, a brake is applied to a water-cooled pulley mounted on the motor shaft as shown in Fig.(6.1). One end of the rope is fixed to the floor via a spring balance S and a known mass is suspended at the other...

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