<p>Which of the following statements is incorrect regarding magnetic field lines?</p><p><b>(a) </b>The direction of magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points</p><p><b>(b)</b>Magnetic field lines are closed curves</p><p><b>(c)</b>If magnetic field lines are parallel and equidistant, they represent zero field strength</p><p><b>(d)</b>Relative strength of magnetic field is shown by the degree of closeness of the field lines </p>