# Finding Kn from ID vs VDS graph

I have the following simple circuit to obtain characteristics of an N type MOSFET.

The gate voltage will be swept from 3 to 6 Volts while the drain voltage will be swept from 0 to 0.5 Volts to obtain ID VS VDS graph for different VGS values. The threshold voltage is calculated from the SAT condition with a different setup and the MOS will always be in triode region with these voltage sweep values.

I am asked to find "the most precise" Kn which is equal to ID/(VDS *( VGS-VT))(Dropping VDS2 for convenience). But what is meant by "the most precise" value?

Unless you measure $$\Vt\$$, you are approximating $$\Kn\$$. $$\Vt\$$ will vary device to device. To find a precise value for $$\Kn\$$, additional measurements must be taken.