Question

study of dependence of current on the potential difference across a resistor and determination of its resistance

Answer 1

As we know by ohm's law:
V=I/R. So we get to know that current is directly proportional to the potential difference. And current is inversely proportional to resistance

Answer 2

according to the ohm's law - at constant physical condition like temperature, the current flowing through a circuit is directly proportional to the potential difference across it's ends

ie. V is directly proportional to I
or, V= IR. (R is the resistance n proportionality constant)