A simple test to check the variation of Ids Vs Vgs when VDS has been set at 6V. It will be easy to see that the ratio ðIds/ðVgs increases when Vds is set at higher voltage values. Just change Vds from 6 to 12 V to check it.A similar consideration is also valid if the ðVgs is taken close to a suitable value for reaching higher IDs.
