Statement I : It is not necessary that eveiy bar magnet has one North Pole and one South Pole. Statement I : Magnetic poles occur in pair.

Statement I is false because every bar magnet must possess both a North Pole and a South Pole. By definition, a bar magnet is a magnetic dipole, and even if it is divided repeatedly, the resulting pieces will always form new dipoles with both poles present. It is impossible to isolate a single magnetic pole, as magnetic monopoles have never been experimentally verified to exist in nature. Statement II is true because magnetic poles always occur in pairs. This fundamental property of magnetism ensures that for every north-seeking pole, there is an equal and opposite south-seeking pole. Since Statement I incorrectly suggests that a bar magnet might not have both poles, while Statement II correctly identifies the paired nature of poles, the correct choice is that Statement I is false and Statement II is true.

Sources

1. [1] https://en.wikipedia.org/wiki/Magnetic_dipole