Question

How potential difference $\left( V \right)$, current $\left( I \right)$ and resistance $\left( R \right)$ are related?

Answer 1

Hint: The relationship between potential difference \[\left( V \right)\] and current $\left( I \right)$ for a given conductor is called Ohm’s law. It is given as $V = IR$. Where, $R$ is the resistance of the given conductor. The flow of electric charge through any given conductor in a unit time is known as the electric current. The potential difference is the difference in potential across the two points of a given conductor.

Complete step by step answer:
The relationship between potential difference $\left( V \right)$ and current $\left( I \right)$ through a conductor was first discovered by German scientist George Simon Ohm. This relationship is called Ohm’s law. The current $\left( I \right)$ flowing through a conductor is directly proportional to the potential difference $\left( V \right)$ across its ends provided the physical condition (temperature, strain, etc.) do not change.
$I \propto V$
$\therefore \dfrac{V}{I} = R$
Where $R$ is a constant of proportionality and is known as resistance of the conductor.

Hence,the relation between $\left( V \right)$, can also be written as $V = IR$.

Note: A conductor is said to have a resistance of one ohm if a potential difference of one volt across its ends causes a current of one ampere to flow through it.The plot between potential differences and electric current flowing through a conductor is given below.

The above graph shows that the relation between potential difference and current flowing through a conductor is linear i.e., a straight line passing through the origin. The slope of the graph is the resistance of the conductor i.e, $\tan \theta = R$. Those conductors which follow the above graph are called ohmic conductors.