In the construction of a full wave rectifier, why is there central tapping in the secondary winding of the power transformer? What's the pure reason behind it? If there was no central tapping, what would be the change?
if there was no central tapping, what would be the change?
Consider this circuit diagram, from the answer you're not satisfied with:
There is no "central tapping" so the two diodes are connected in series. In a series connected circuit, the current through each circuit element is identical.
Now, note that D1 allows only a clockwise current while D2 allows only a counter-clockwise circuit. The only solution that satisfies both constraints is zero current.
So, without the center-tap, there is zero current in the secondary circuit and thus, by Ohm's Law, zero voltage across the resistor R.