Lesson Plan

• Describe the magnetic field pattern around a straight current‑carrying wire and state its direction using the right‑hand rule.
• Explain why the field inside a solenoid is uniform and parallel to its axis.
• Carry out the prescribed experiment, record compass deflections, and produce accurate field‑line sketches for both configurations.
• Analyse how reversing the current changes field direction and compare observations with theoretical formulas.

• Power supply or battery
• Ammeter
• Straight copper wire (≈ 1 m)
• Solenoid (≈ 200 turns, 10 cm long)
• Connecting leads
• Compass or small magnetic needles
• Paper sheet, pencil and ruler
• Worksheet for recording observations

Begin with a brief demo showing a compass needle swing when a current is switched on, prompting recall of the right‑hand rule. Review the formula for the magnetic field around a straight conductor and the concept of a uniform field inside a solenoid. Explain that today students will design and carry out an experiment to map these fields, and success will be measured by accurate sketches and clear explanations.

1. Do‑now (5 '): Students answer a short question on the direction of the magnetic field around a current‑carrying wire.
2. Mini‑lecture (10 '): Recap the right‑hand rule, the relevant formulas, and the experimental set‑up.
3. Group activity – straight wire investigation (15 '): Build the circuit, place the compass at several distances, record deflections, then reverse the current and repeat.
4. Group activity – solenoid investigation (15 '): Replace the wire with the solenoid, record compass behaviour at the centre and ends, and repeat with reversed current.
5. Data consolidation (10 '): Teams tabulate observations and sketch the inferred field lines for both setups.
6. Concept check (5 '): Quick exit ticket where students predict the field direction for a new current configuration.
7. Homework assignment: Calculate magnetic field strengths for given currents and distances and write a short paragraph on a real‑world application (e.g., electromagnets).

Students summarise the circular field pattern around the straight wire and the uniform axial field inside the solenoid, linking both to the right‑hand rule. They complete an exit ticket predicting field direction after current reversal. For homework they compute magnetic field values using the provided formulas and reflect on practical uses of these field patterns.