Let each MOSFET offers resistance Rds.
When they are connected in parallel, their equivalent resistance is Rds//Rds.
=Rds/2.
Therefore, equivalent resistance will go down by half of the MOSFET resistance.
A MOSFET Operators Circuit in a resis to as a Fwe conne ct another MOSFET identical in parialle veristance wAl go u...