How does a solenoid behave like a magnet? Can you determine the north and south poles

A solenoid has a large number of close, insulated circular turns. The magnet at the centre of current carrying circular wire is along the axis; so when current is passed in a solenoid, the magnetic fields due to all circular turns are added and hence the field line becomes just as for a bar magnet. 

Yes, we can determine the north and south poles of a current carrying solenoid with the help of a bar magnet. For this we suspend the bar magnet freely and note its ends pointing along north and south directions and mark on these ends N (north pole) and S (south pole). 

Now we bring N-pole near one end of freely suspended current carrying solenoid; if there is repulsion, then that end of solenoid is N-pole and other S-pole; but if there is attraction, then that end of solenoid is S-pole and the other is N-pole.

When electric current flows through a solenoid, magnetic field is set up around the solenoid. The pattern of the magnetic field is same as that of the magnetic field of a bar magnet. One end of the solenoid behaves as north pole and the other end of the solenoid behaves as south pole.

To determine the north and south poles of a current carrying solenoid with the help of a bar magnet, suspend it with a strong thread. Now bring the north pole of a bar magnet towards one end of the solenoid. If the solenoid attracts towards the magnet then the face of the solenoid is south pole. If the bar magnet moves away from the solenoid, then the face of the solenoid is the north pole.