What is Ohm’s law? Explain how it is used to define the unit of resistance.

Ohm’s law helps in understanding the relation between current, I and potential difference, V. The law states that at constant temperature, the current flowing through a conductor is directly proportional to the potential difference across its ends. The mathematical representation of the law is:

Let I be the current flowing through a conductor and V be the potential difference across the ends of the conductor. Then from Ohm’s law we know that

I ∝ V V ∝ I V = RI

R = v/I Where,

R is resistance offered by the conductor which is constant. The unit of resistance is ohm. If V = 1 volt and I = 1mp, then R = 1/1 = 1ohm.

Therefore, 1 ohm is defined as the resistance of a conductor such that when the potential difference of 1 volt is applied to its ends, a current of 1 amp flows through it.