The electric current and the voltage are related by the law named Ohm’s Law, which states that the electric current flowing in any conductor is directly proportional to the voltage difference between the ends of the conductor. That is, $V\\propto I$ and it is written after resolving as V = IR where R is the proportionality constant and is called the resistance of the conductor. The resistance of the conductor is the opposition to the flow of current passing through the conductor. The graph between V and I is a straight line with a slope R.