The potential difference, V, across the ends of a given metallic wire in an electric circuit is directly proportional to the current flowing through it, provided its temperature remains the same. This is called ________ law.

Ohm's

The correct answer is option 3. Ohm's.

The potential difference, \( V \), across the ends of a given metallic wire in an electric circuit being directly proportional to the current flowing through it, provided its temperature remains the same, is described by Ohm's Law.

Ohm's Law states that the current (\( I \)) flowing through a conductor between two points is directly proportional to the voltage (\( V \)) across the two points, given a constant temperature. Mathematically, Ohm's Law is represented as:

\[ V = I \times R \]

where:

\( V \) is the potential difference (voltage) across the conductor,

\( I \) is the current flowing through the conductor, and

\( R \) is the resistance of the conductor.

This relationship holds true for metallic conductors under constant temperature conditions and is fundamental in understanding and analyzing electrical circuits. Therefore, the correct term for this relationship is Ohm's Law.