Consider the following statements: Statement - I : The magnetic field lines emerge from the north pole and merge at the south pole of a bar magnet. Statement - II : The direction of magnetic field is taken to be the direction in which the north pole of a compass needle moves. Statement - III : There is no field inside a bar magnet. Statement- IV : The relative strength of the magnetic field is shown by the degree of closeness of the field lines. Which of the above statement(s) is/are correct?

Statement I: Magnetic field lines emerge from the North pole and enter the South pole outside the magnet, forming closed loops. Inside the magnet, they go from South to North. The statement is conventionally understood to describe the field outside the magnet, making it correct. Statement II: The direction of the magnetic field at any point is defined as the direction in which the north pole of a compass needle would point if placed at that point. This statement is correct. Statement III: There is a magnetic field inside a bar magnet. The field lines continue from the South pole to the North pole within the magnet, completing the loops. This statement is incorrect. Statement IV: The density or closeness of magnetic field lines in a region indicates the strength of the magnetic field in that region. Where lines are closer, the field is stronger (e.g., near the poles); where they are farther apart, the field is weaker. This statement is correct.