George Simon Ohm, a German Scientist put across a law known as Ohm’s law, from which the relationship between the current flowing through a wire (I) and the potential difference across its ends (V) can be obtained. As per the law, if the physical state of a conductor remains constant, the current (I) flowing through it is directly proportional to the potential difference (V) between its two ends. Given is the formula,
I ∝ V
I = kW ( k is the constant of proportionality)
Meanwhile, V = I × (1/k ) ( Here, 1/k = R =Resistance of the conductor)
So replace 1/k with R and you get
V= I × R = IR.
Thus, R = V/ I. This is ohm’s law.