While looking at an end of a current carrying solenoid, a student finds that the direction of current is clockwise direction. The end of the solenoid behaves as 

CONCEPT:

Right-hand thumb rule:

• According to this rule, if we imagine the linear wire conductor to be held in the grip of the right hand so that the thumb points in the direction of the current, then the curvature of the fingers around the conductor will represent the direction of the magnetic field lines. 

EXPLANATION:

• From the above, it is clear that according to the Right-hand thumb rule, the thumb points in the direction of the electric current in a straight current-carrying wire.
• The end of the solenoid carrying current:

⇒ Anticlockwise: North Pole

⇒ Clockwise: South Pole

• This is obtained using the right-hand thumb rule.
• If you curl the fingers of the right hand in the direction of the current, the direction of the curve fingers gives the direction of the induced magnetic field.
• Thus, if the current is in the clockwise direction at either end, the magnetic field direction is into the end i.e. the magnetic field lines terminate at that end and the end acts as a south pole.