How to calculate the efficiency of full wave rectifier? Also, prove that efficiency of Full wave rectifier is 81.2%

 

How to calculate the efficiency of full wave rectifier? Also, prove that efficiency of Full wave rectifier is 81.2%

Write the expressions for DC power out and AC Power In. The ratio of those two expression will be the efficiency, just like in all the other cases where you have Power Out < Power IN

 

The efficiency depends upon the diode drops at the load current and the AC voltage value . The efficiency is not a fixed value independent of these variables.

 

The efficiency depends upon the diode drops at the load current and the AC voltage value . The efficiency is not a fixed value independent of these variables.

Power Out and Power In can be measured or theoretical. Power out definitely depends on the diode drops.

 

...prove that efficiency of Full wave rectifier is 81.2%

I can prove that it is almost NEVER that exact value, except in a very specific set of circumstances, which you have not provided us.