In the given diagram, if the arrow shows the direction of current then where will the north- pole is assumed to be
right end of solenoid
Let's use the right-hand thumb rule at the left corner of the solenoid. We will see that the fingers curl inwards showing that the magnetic field lines run from left end to right end, and we know the magnetic field lines run from south to north inside a magnet. So, the left end becomes south-pole while right end becomes north-pole.