Why temperature need to be constant in ohm's law?

Dear Student,

Ohm's law states that the current through a conductor between two points is directly proportional to voltage difference across two points.

$I\propto V$

Introducing the proportionality constant

$$\begin{gathered} I=GV \\ Or \\ V=IR \end{gathered}$$

Here R or G are constant terms which should not change.

You know if we increase temperature of a conductor, its resistence changes. It means that the proportionality constant has changes which means current is no longer proportional to voltage difference in temperature changing enviroment.

So, temperature is assumed to be constant in Ohm's law.

Hope it is clear.

Regards,
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