Which of the following statements about magnetic fields are true?
There are no magnetic field lines outside the magnet.
Magnetic field lines point outward from the south pole of a magnet.
There are no magnetic field lines unless iron filings are present.
Magnetic field lines point in towards the north pole of a magnet.
Magnetic field lines point outward from the north pole of a magnet.
None of these.
The correct answer and explanation is :
The correct statements about magnetic fields are:
- Magnetic field lines point inward toward the north pole of a magnet.
- Magnetic field lines point outward from the south pole of a magnet.
Explanation:
Magnetic fields are invisible force fields produced by moving electric charges (electric current) or magnetic materials like magnets. These fields can be observed and represented by magnetic field lines, which help visualize how magnetic forces operate in space.
- There are no magnetic field lines outside the magnet:
- This statement is false. Magnetic field lines exist both inside and outside a magnet. Magnetic field lines form a closed loop, emerging from the north pole of a magnet and entering into the south pole, and extending outside the magnet, forming complete loops.
- Magnetic field lines point outward from the south pole of a magnet:
- This statement is false. Magnetic field lines point into the south pole, not outward. Field lines exit from the north pole and curve around to enter the south pole.
- There are no magnetic field lines unless iron filings are present:
- This statement is false. Magnetic fields are always present around magnets or moving charges, whether or not iron filings are used to visualize them. Iron filings simply make it easier to see the invisible field lines.
- Magnetic field lines point in toward the north pole of a magnet:
- This statement is false. Magnetic field lines always point outward from the north pole of a magnet and curve inward to the south pole.
- Magnetic field lines point outward from the north pole of a magnet:
- This statement is true. Magnetic field lines originate at the north pole and curve around to the south pole.
Magnetic field lines follow certain conventions and are directed from north to south outside a magnet, forming a continuous loop. These lines help illustrate the direction and strength of magnetic forces in different regions around the magnet.