Lesson Plan

• Describe the Hall effect and how it relates Hall voltage to magnetic flux density B.
• Explain the calibration and proper orientation of a Hall probe for accurate B measurements.
• Apply the relation F = I L B to calculate the magnetic force on a current‑carrying conductor using measured B.
• Analyse common sources of error in Hall‑probe experiments and suggest ways to minimise them.

• Hall probe with display or data‑logger
• Straight copper wire of known length
• Variable DC power supply
• Ammeter
• Ruler or laser pointer for deflection measurement
• Supports/clamps to hold the wire
• Projector/computer for visual aid
• Safety goggles

Begin with a quick question: “What force acts on a wire carrying current in a magnetic field?” Students recall the Lorentz force law, linking it to real‑world devices such as motors. Review that today’s success criteria are to correctly use a Hall probe to obtain B and then compute the magnetic force on the wire.

1. Do‑now (5 min): Solve a short problem using F = I L B to refresh the Lorentz force concept.
2. Mini‑lecture (10 min): Explain the Hall effect, probe calibration, and orientation requirements.
3. Teacher demonstration (10 min): Zero the Hall probe, then measure B near a current‑carrying wire while varying current.
4. Hands‑on activity (20 min): Students set up the wire, connect the power supply and ammeter, record B with the probe, measure wire deflection, and calculate F.
5. Data analysis & error discussion (10 min): Groups compare calculated force with deflection‑based estimates and identify sources of error.
6. Exit ticket (5 min): Write one accurate statement about how a Hall probe is used to determine magnetic force.

Summarise how the Hall probe provides a direct measurement of B, which together with known I and L gives the magnetic force. Collect exit tickets and assign a brief homework: research another magnetic‑field sensor (e.g., fluxgate or SQUID) and compare its advantages to the Hall probe.