What is an acceptable ending to the following sentence: “Magnetic field lines…”
Can cross each other.
Originate from monopoles.
All of the above.
Are not present without iron filings.
Form closed loops.
None of these.
The correct answer and explanation is :
The correct answer is “Form closed loops.”
Explanation:
Magnetic field lines are used to represent the direction and behavior of magnetic fields in space. These lines are drawn from the north pole of a magnet and curve around to the south pole, showing the continuous nature of the magnetic field.
Let’s go through the options to clarify why “Form closed loops” is the correct answer:
- “Can cross each other”: This is incorrect. Magnetic field lines do not cross each other. The reason for this is that at any given point in space, the magnetic field has a well-defined direction. If the field lines were to cross, it would imply that the magnetic field has two different directions at the same point, which is impossible.
- “Originate from monopoles”: This is also incorrect. Magnetic monopoles (isolated north or south poles) have never been observed in nature. Magnetic field lines originate from the north pole of a magnet, but in real-world situations, every magnetic dipole (such as a bar magnet) has both a north and a south pole. Magnetic field lines form a closed loop between the two poles.
- “All of the above”: Since some of the previous statements are false, this cannot be the correct answer.
- “Are not present without iron filings”: This statement is misleading. Magnetic fields exist whether or not there are iron filings. Iron filings are often used in demonstrations because they align along the magnetic field lines, making the field visible to the human eye, but the field itself exists even without them.
- “Form closed loops”: This is the correct and most accurate statement. Magnetic field lines always form closed loops. They emerge from the north pole and curve around to the south pole. Inside the magnet, they continue from the south pole back to the north pole, creating a continuous, closed-loop structure. This behavior is in accordance with the laws of electromagnetism, particularly Gauss’s law for magnetism, which states that there are no magnetic monopoles.
- “None of these”: This is incorrect since “Form closed loops” is a valid statement.
Image Explanation:
Below is an image showing magnetic field lines around a bar magnet. The lines form closed loops, originating at the north pole and curving around to the south pole.
Here is an illustration showing magnetic field lines around a bar magnet. The lines form closed loops, starting at the north pole, curving around, and returning to the south pole. This image visually represents the continuous nature of magnetic fields, which is consistent with the correct answer that magnetic field lines “form closed loops.”