I have a question in regards to potentiometry. How can Vo be changed to allow a null current reading? And why can a null current be registered for sufficiently small Vo. :confused:

V=IR, where V is the voltage, I is the current and R is the resistance.

So you can see that (as R is a set value and doesn't change) any value of V will require a value for I. Therefore if V=0 I =0. Hope so anyway.

Yeah you can minimise V by turning off the apparatus.

Heh.

You need to give us a better idea of what you are doing, what experiment you are performing, and then we can give you a better answer.