I want to know how we can create a negative voltage using potentiometer.
please don't use formula ,just explain it in detail with real direction of electrons.
tnx
Your thread title tells us nothing. Next time use a title that tells us something about your problem.
A potentiometer can't "create" a negative voltage from a positive voltage. It can only affect the value of voltage that you have.
If you really need a negative voltage then you will have to use a switching inverter supply to generate that.
What's the purpose of the negative voltage?
Is it to bias the transistor gate?
To generate a reverse bis for the gate-source junction of an N-JFET a resistor is often placed from source to ground, then the drain-source bias current generates a positive source voltage with respect to the gate (giving a negative Vgs).