what is difference in voltage regulation in half& full wave rectifiers?


or these are same for both

 

The first answer is that rectifiers are not regulators. Rectifiers make no attempt to regulate voltage.

The second answer is that a full wave rectifier will require half the capacitance to reduce voltage sag between power pulses, compared to a half wave rectifier.

 

The word "regulation" in this context refers to the variation of output voltage with load current. This term is also applied to transformers. http://www.allaboutcircuits.com/vol_2/chpt_9/6.html

Typically for a given value of reservoir capacitance full-wave rectifiers give better regulation than half-wave, because the ripple sag time is approximately halved.

A bridge (Graetz) rectifier however has two diodes in the path instead of one for the half-wave type, so the rectifier drop can be larger, although this is somewhat offset by the fact that only half the mean current passes through any one diode.