Why does the current in MOSFET have a quadratic function (explain logically without using the integration method)?
In an enhancement mode MOSFET, voltage applied to the gate terminal increases the conductivity of the device.

Logically, think of it in terms of the conduction gap being closed with applied gate -source voltage as a 1/r² effect as the electric field is increased so on a log scale it might look like a linear slope.


Nanowire FET By Saumitra R Mehrotra &amp; Gerhard Klimeck, modified by Zephyris - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11299479