Question

Choose the incorrect statement from the following regarding magnetic lines of the field

• A. The direction of the magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points
• B. Magnetic field lines are closed curves
• C. If magnetic field lines are parallel and equidistant, they represent zero-field strength
• D. The relative strength of the magnetic field is shown by the degree of closeness of the field lines

Answer 1

The correct option is C

If magnetic field lines are parallel and equidistant, they represent zero-field strength

The explanation for the correct option:

1. Magnetic field lines are the imaginary lines around the magnet.
2. The density of a field's line exhibits its magnitude.
3. The magnetic field of a magnet is the strongest around its South and North Poles and weakens as it goes away from the poles
4. The magnetic field lines do not cross over each other.
5. They have a uniform magnetic field and no magnetic field strength.
6. The magnetic field is uniform if the lines are parallel and equidistant in a magnetic field.

The explanation for the incorrect option(s):

Option A:

1. Field lines are used to display the direction of the magnet-generated field lines.
2. They also show the magnetic force's path. We can easily calculate the magnetic force and magnetic field using these lines.
3. A magnetic field line is a path that a free north-pole tends to travel along.
4. A small compass needle is needed to determine the path of a magnetic field.
5. The path of a magnetic field at that place is specified by the North - pole of the compass.

Option B:

1. Magnetic field lines are closed curves that begin at the magnet's north pole and end at the south pole.
2. Magnetic field lines are closed curves that propagate from the north pole outside the magnet's body to the magnet's body and from the south pole to the north pole inside the magnet's body.

Option D:

1. A magnetic field is a vector field that explains the magnetic influence of any other moving charges or magnetized materials on an electric charge.
2. A charge moving in a magnetic field will experience a force perpendicular to its velocity and the magnetic field.
3. The degree of closeness describes the relative strength of magnetic field lines.
4. At any point along the line, arrows indicate their direction.

Hence, option C is correct.