Understanding Ohm's Law: Definition, Formula, and V-I Graph

Ohm’s Law

OHM’S LAW

A German physicist, Georg Simon Ohm established the relation between the potential difference and current, which is known as Ohm’s Law. This relationship can be understood from the following activity.

Figure 4.4 Electric circuit to understand Ohm's law.

According to Ohm’s law, at a constant temperature, the steady current ‘I’ flowing through a conductor is directly proportional to the potential difference ‘V’ between the two ends of the conductor.

I ∝ V. Hence, 1/V = constant.

The value of this proportionality constant is found to be 1/R

V = I R       (4.3)

Here, R is a constant for a given material (say Nichrome) at a given temperature and is known as the resistance of the material. Since, the potential difference V is proportional to the current I, the graph between V and I is a straight line for a conductor, as shown in the Figure 4.5.

Figure 4.5 Relation between potential difference and current.

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail

10th Science : Chapter 4 : Electricity : Ohm’s Law |