Which of the following statement(s) is/are incorrect?

(A) A current carrying loop may act as a magnetic dipole whose magnetic moment may depend on its area and the number of turns.
(B) A linear solenoid carrying current, may act as a bar magnet.
(C) The magnetic lines of forces due to the current carrying solenoid makes closed curves like in a bar magnet.
(D) The magnetic field inside a solenoid is perpendicular to its axis.

Choose the correct answer from the given options:

(D) only

The correct answer is Option (4) → (D) only

(A) Correct — Magnetic moment of a loop is $M = nIA$, depends on area and number of turns.

(B) Correct — A long solenoid produces a field similar to a bar magnet.

(C) Correct — Magnetic field lines of a solenoid are closed, just like a bar magnet.

(D) Incorrect — Magnetic field inside a solenoid is parallel to its axis, not perpendicular.

Final Answer: (D)