Question

If we have a bar magnet, we broke it in two pieces but when we try to join it from the place we have broke it in two pieces then they repel each other but if we rotate one of them by 180 degrees they attract each other. Why?

Answer 1

Question is wrongly formed.   The poles attract at the cut.

 |                                                      |
 |   N                                           S   |
 |                                                     |

if it is split into two pieces , it becomes: 

 |                           |                          |
 |   N                 S  |  N                 S   |
 |                          |                           |

Hence the poles formed at the cut or break, are opposite. They attract each other.