Best examples of examples of investigating magnetic fields in physics labs

Starter examples of investigating magnetic fields with magnets and compasses

The most accessible examples of investigating magnetic fields start with permanent magnets and compasses. These are low-cost, low-risk, and visually satisfying. They also build the intuition students need before current-carrying wires enter the story.

A classic example of a first investigation is mapping the field around a bar magnet using a compass. Place the magnet at the center of a sheet of paper, trace its outline, and then move a small compass around it, marking the direction of the needle at many points. Connect the arrows into smooth curves and you get a field-line diagram that matches what you see in textbooks. This is one of the best examples of how to turn an invisible field into visible data.

A variation that many teachers like in 2024 is to compare different magnet geometries. Students repeat the mapping procedure with a bar magnet, a horseshoe magnet, and a ring magnet (from an old speaker). These examples include discussions about where the field is strongest, how closely spaced the lines are, and how magnet shape changes the pattern. The activity naturally leads to questions about magnetic poles and how fields extend into surrounding space.

For a quick visual demonstration, iron filings on a sheet of paper above a magnet still work beautifully. While this isn’t as quantitative as compass mapping, it gives another example of investigating magnetic fields that feels almost like a physics “instant replay” — you see the field pattern appear in seconds.

Examples of examples of investigating magnetic fields from current-carrying wires

Once students can read field lines around permanent magnets, it’s time to bring in electric current. These examples of investigating magnetic fields connect directly to how power lines, motors, and transformers operate.

One widely used example of a simple experiment is the straight wire and compass setup. Run an insulated wire horizontally above a small compass, connect it to a DC power supply, and watch the needle deflect when current flows. Reverse the current and the compass swings the other way. This is a clean way to test the right-hand rule and to show that moving charges create magnetic fields.

A slightly more advanced version uses a vertical wire and a set of compasses arranged in a circle around it. When current flows, the compasses line up tangentially, tracing out circular field lines predicted by Ampère’s law. These examples include qualitative and quantitative work: students can vary current and measure how needle deflection changes, relating it to field strength.

Another of the best examples of investigating magnetic fields from currents is the coil (solenoid) experiment. Wrap many turns of wire around a cardboard tube, connect to a power supply, and place a compass at different positions along and around the coil. The field inside the coil behaves like that of a bar magnet, and outside the coil, the pattern is more complex. These examples of examples of investigating magnetic fields are ideal for linking magnetism to electromagnets in doorbells, relays, and MRI scanner magnets.

Teachers updating their lab sequences for 2024 often add a comparison between air-core and iron-core solenoids. Insert a soft iron nail into the solenoid and measure how many paper clips it can pick up at a given current. This gives a very direct, tangible example of how magnetic materials boost field strength.

Real examples of investigating magnetic fields with sensors and smartphones

In the last decade, one of the best examples of modernizing magnetism labs is the use of digital sensors. Today’s smartphone magnetometers are sensitive enough to support serious classroom investigations.

A popular example of a 2024-ready lab is mapping the magnetic field around a solenoid using a smartphone app that reads the built-in magnetometer. Students move the phone along the solenoid axis and record field values at fixed intervals. Plotting field strength versus position shows a nearly uniform field inside and a rapid drop-off near the ends. These real examples of investigating magnetic fields make the connection to data science: students can export readings to a spreadsheet and fit theoretical curves.

For more precision, many high school and undergraduate labs now use dedicated Hall-effect sensors or Gaussmeters. These examples include measuring Earth’s magnetic field, characterizing permanent magnets, and verifying the 1/r dependence of the field around a long straight wire. Hall sensors are based on the Hall effect, which is still an active research area in condensed matter physics; students can look up background material from university physics departments such as MIT OpenCourseWare or similar resources.

Another real example of investigating magnetic fields with sensors involves mapping the stray fields around everyday devices. Students can measure the field near:

• The side of a laptop
• The transformer brick of a charger
• The door seal of a refrigerator
• The coil in a wireless charging pad

These examples of investigating magnetic fields make the topic feel less abstract and lead naturally into safety discussions, such as exposure limits around MRI facilities (see background from the U.S. National Institutes of Health: https://www.nih.gov/).

Best examples of investigating magnetic fields in motion: motors, rails, and levitation

Static setups are fine, but the best examples of investigating magnetic fields often involve motion. This is where magnetic fields stop being just patterns on paper and start looking like technology.

One classic example of a dynamic experiment is the simple DC motor build. Students wind a small armature coil, mount it on paper-clip bearings, place it between the poles of a strong magnet, and connect it to a battery with a basic commutator. When current flows, the coil experiences a torque in the magnetic field and spins. This is not only an example of investigating magnetic fields, but also of seeing how magnetic forces convert electrical energy into mechanical work.

Another memorable example is the homopolar motor: a battery, a magnet, and a piece of wire arranged so that the wire spins around the battery. This provides a very direct, low-friction demonstration of the force on a current-carrying conductor in a magnetic field.

For more advanced classes, a rail gun or linear motor demonstration makes a powerful impression. Two parallel conducting rails with a movable conducting bar between them, placed in a strong magnetic field, will drive the bar along the rails when current flows. While safety and current limits matter here, it stands as one of the best examples of investigating magnetic fields in a way that echoes maglev trains and industrial linear motors.

These dynamic examples include opportunities to measure force, acceleration, and power. Students can compare measured values to predictions from F = I L × B. That connection between experiment and equation is where magnetic fields stop being mysterious and start being measurable.

Real examples of investigating magnetic fields in Earth and space

Not all examples of investigating magnetic fields happen on a lab bench. Some of the most interesting real examples involve Earth’s magnetic field and space weather.

A straightforward classroom example of an experiment is measuring Earth’s horizontal magnetic field using a tangent galvanometer or a simple coil and compass arrangement. By balancing the torque of Earth’s field against the field of a known current in a circular coil, students can estimate the field strength at their location. Data can be compared against values reported by agencies such as the U.S. Geological Survey (https://www.usgs.gov/), which monitors Earth’s magnetism.

Another example for students with internet access is using real-time data from space weather monitoring sites. NASA and other agencies publish magnetometer data from satellites that track changes in Earth’s field during solar storms. Teachers can build a project where students correlate spikes in magnetic field data with aurora reports or satellite anomaly logs. These real examples of investigating magnetic fields show that magnetism is not just a lab curiosity; it affects GPS accuracy, power grid stability, and communication systems.

Even a simple outdoor compass survey around the school grounds can be revealing. Students may detect local anomalies due to buried pipes, steel building frames, or power cables. These examples include mapping and interpreting small deviations from the expected north direction, tying back to the idea that any current or magnetic material contributes to the total field.

Examples of examples of investigating magnetic fields in modern tech: wireless power and MRI

If you want students to see the direct link between classroom experiments and high-end technology, there are some standout examples of examples of investigating magnetic fields you can adapt conceptually, even if you can’t replicate them fully.

Wireless charging pads for phones use oscillating magnetic fields to transfer energy between coils. A table-top example of investigating this uses two coils: one driven by an AC source, the other connected to a small bulb or LED. By varying the distance and alignment between the coils, students can see how coupling efficiency changes. These examples include measuring induced voltage with a multimeter and comparing results to theoretical predictions from Faraday’s law.

At the medical end of the spectrum, MRI scanners use very strong magnetic fields and radiofrequency pulses to image the human body. While you obviously cannot build an MRI in a school lab, you can use simple experiments with permanent magnets and coils to demonstrate basic principles of nuclear magnetic resonance. Background reading from academic medical centers such as Harvard Medical School (https://hms.harvard.edu/) helps connect the dots between the classroom and clinical imaging.

These high-tech examples of investigating magnetic fields are especially effective in 2024–2025 because students encounter them daily: wireless earbuds, NFC payment terminals, and even anti-theft tags in stores depend on magnetic fields and induction.

Designing your own examples of investigating magnetic fields

Once students have seen a range of examples of investigating magnetic fields, they are usually ready to design their own experiments. This is where inquiry-based learning and real engineering thinking come in.

A good strategy is to ask students to pick a device that obviously uses magnetism — a speaker, a hard drive, an electric toothbrush — and propose an example of an experiment that measures or visualizes the fields involved. They might use a smartphone magnetometer to map the field around a speaker cone, or a compass array to see how a rotating magnet in a toothbrush motor affects the local field.

The best examples of student-designed investigations include a clear question, a simple but repeatable method, and a way to compare results with theory or published data. For instance, a group might investigate how the field around a coil drops with distance and compare their measurements to the predictions of the Biot–Savart law, using open educational resources from universities such as MIT or Stanford.

By this stage, students are not just reproducing classic examples of examples of investigating magnetic fields; they are creating new ones tailored to their interests and tools. That shift — from following instructions to asking their own questions — is where magnetic field experiments really start to matter.

FAQ: common questions about examples of investigating magnetic fields

Q: What are some simple classroom examples of investigating magnetic fields?
Some of the simplest examples include mapping field lines around a bar magnet with a compass, using iron filings to visualize patterns, and observing compass deflection near a current-carrying wire. These require minimal equipment and work well in middle school and early high school.

Q: What is an easy example of a magnetic field experiment using electricity?
A very accessible example of an electric-based experiment is placing a straight wire above a compass, then switching a DC current on and off. Students see the compass needle rotate when the current flows, directly showing that moving charges produce magnetic fields.

Q: Are there real examples of investigating magnetic fields with smartphones?
Yes. Modern phones contain magnetometers that can measure field strength. Students can map the field around magnets, coils, or household devices, record values, and plot them. Many physics education groups and universities now publish smartphone-based lab guides as part of their outreach materials.

Q: How do these examples connect to real-world technology?
Nearly every electromagnetic technology — motors, transformers, MRI scanners, wireless chargers, maglev trains — is built on the same field patterns and forces seen in these experiments. The lab-scale examples of investigating magnetic fields are scaled-down versions of the physics that drives modern power and communication systems.

Q: Where can I find more background on magnetic fields and safety?
For general physics background, university physics departments and open course materials from .edu sites are reliable. For health-related questions about strong magnetic fields, such as MRI environments, U.S. government and medical sites like the National Institutes of Health (https://www.nih.gov/) and major medical centers such as the Mayo Clinic (https://www.mayoclinic.org/) provide accessible explanations and safety guidelines.