The correct answer is option 4. This statement is not correct. Field lines do exist within a bar magnet. Magnetic field lines are used to represent the direction and strength of a magnetic field. They are always closed loops, meaning they form continuous curves that loop back into themselves.

Option 1 is correct. Magnetic field lines can emanate from a point. This is seen in cases where a single magnetic pole exists, such as in a magnetic monopole (which has not been observed yet).

Option 2 is correct. Magnetic field lines do not cross each other. If they were to cross at a certain point, it would imply that the magnetic field has multiple directions at that point, which is not possible.

Option 3 is correct. Field lines between two poles cannot be precisely straight lines at the ends. They curve outward from one pole and curve inward towards the other pole, forming an arched shape.

In summary, the only statement that is incorrect is option 4, as there are field lines within a bar magnet.