Which of the following is correct with regard to the properties of magnetic lines of force?
1. Magnetic lines of force do not intersect each other
2. Each line is a closed and continuous curve
3. They are crowded near the poles, where the magnetic field is strong
1
Only 1
2
Only 1 and 3
3
Only 2 and 3
4
More than one of the above
5
None of the above