But, that doesnât mean students have to take them all in the same week. Our class structure allows us to provide 5 cycles of classes for every 30-day period. As long as students take the classes in order, (Class 1, Class 2, Class 3, Class 4), they are free to switch between any of the cycles for that 30-day period. The only other requirement is that all 4 classes must be completed within 30 days of the first class.
Re: Advantages of three phase systems over single phase. The big advantage with 3 phase mains is that any electric motor connected to it is more efficient, has smother running and uses less parts so is more reliable. There is also a slight advantage in using 3 phase transformers over single phase ones.
Both three-phase and single-phase devices can be powered from a three-phase supply. A three-phase circuit is a combination of three single-phase circuits. The current, voltage, and power relations of balanced three-phase AC circuits can be studied by applying the rules that apply to single-phase circuits.