Suggest a simple experiment to map the magnetic field around a magnet using a compass.

Suggest a simple experiment to map the magnetic field around a magnet using a compass.

• A. Move a compass around the magnet and plot the direction of the needle; the plotted lines show the field.
• B. Use a voltmeter to measure field strength.
• C. Submerge in water and observe.
• D. Use a ruler to measure length of field lines.

Answer: (A)

Magnetic fields reveal themselves by the direction a compass needle points. A compass needle is a tiny magnet, so it aligns with the local magnetic field. By moving the compass around the magnet and noting the direction the needle points at many different positions, you can sketch lines that trace the field. When you join these directions, you get a map of the field pattern around the magnet, showing that the field lines emerge from the magnet’s north pole and loop around back to the south pole. This method is the right choice because it directly uses the compass to sense the field’s direction, which is what “mapping the magnetic field” means. A voltmeter isn’t suited for mapping a magnetic field around a magnet, and submerging in water or using a ruler doesn’t reveal the field lines or their directions.

Magnetic fields reveal themselves by the direction a compass needle points. A compass needle is a tiny magnet, so it aligns with the local magnetic field. By moving the compass around the magnet and noting the direction the needle points at many different positions, you can sketch lines that trace the field. When you join these directions, you get a map of the field pattern around the magnet, showing that the field lines emerge from the magnet’s north pole and loop around back to the south pole.

This method is the right choice because it directly uses the compass to sense the field’s direction, which is what “mapping the magnetic field” means. A voltmeter isn’t suited for mapping a magnetic field around a magnet, and submerging in water or using a ruler doesn’t reveal the field lines or their directions.