Choose the correct statement regarding Ohm's law.

• According to Ohm's law, if the physical circumstances, like temperature, are constant, the current flowing through a wire is directly proportional to the potential difference applied across its ends.
  V = IR
• Where V is the potential difference R is resistance and I is current.
• Ohm's law is only not valid for conductors, it is not valid for all conductors.

Therefore,  'The temperature must be constant for validation of this law.' is the correct response.