For a current in a long straight solenoid, N and S poles are created at the two ends. Among the following statements, the incorrect statement is :

Let us evaluate each statement based on the NCERT textbook:

• Statement (a) is correct: The NCERT text states, 'The field lines inside the solenoid are in the form of parallel straight lines. This indicates that the magnetic field is the same at all points inside the solenoid. That is, the field is uniform inside the solenoid.'
• Statement (b) is correct: The NCERT text states, 'A strong magnetic field produced inside a solenoid can be used to magnetise a piece of magnetic material, like soft iron, when placed inside the coil.'
• Statement (c) is incorrect: The NCERT text states, 'Compare the pattern of the field with the magnetic field around a bar magnet (Fig. 12.4). Do they look similar? Yes, they are similar.' Therefore, claiming that the pattern of the magnetic field associated with a current-carrying solenoid is different from that of a bar magnet is incorrect.
• Statement (d) is correct: Since the magnetic field direction is directly dependent on the direction of the current, reversing the current reverses the direction of the magnetic field lines, thereby exchanging the positions of the North (N) and South (S) poles.

Since the question asks for the incorrect statement, option (c) is the correct choice.