Lesson Plan

• Recall the relationship V = IR and rearrange it to solve for I or R.
• Apply V = IR to determine currents and voltages in series and parallel resistor networks.
• Calculate the resistance of a conductor from its resistivity using R = ρ L⁄A.
• Explain how temperature affects resistivity and adjust resistance calculations accordingly.
• Convert units correctly (e.g., mm² to m²) when solving resistance problems.

• Projector or interactive whiteboard
• Printed worksheets with circuit diagrams and practice questions
• Resistor kits (various values) and breadboard
• Scientific calculators
• Rulers/measuring tape for wire length measurements
• Handout of common material resistivities

Begin with a quick “What happens to a bulb’s brightness when you double the voltage?” hook to activate curiosity. Review that students already know V = IR from previous work on simple circuits. State that by the end of the lesson they will reliably use V = IR, series/parallel formulas, and the resistivity equation to solve real‑world problems.

1. Do‑now (5'): short quiz on V = IR and unit conversion.
2. Mini‑lecture (10'): review V = IR, series & parallel resistance formulas, and R = ρ L⁄A with example calculations.
3. Demonstration (8'): build a series‑parallel circuit on a breadboard, measure voltage and current with a multimeter, and discuss results.
4. Guided practice (12'): students work in pairs to solve Worked Example 1 (resistivity) and Worked Example 2 (mixed circuit), teacher circulates for support.
5. Temperature‑effects activity (5'): calculate resistivity change for a nichrome wire using ρ(T) = ρ₀[1+α(T‑T₀)].
6. Check for understanding (3'): exit‑ticket – one problem requiring use of both V = IR and R = ρ L⁄A.

Summarise how V = IR, series/parallel rules, and material resistivity together let us predict circuit behaviour. Collect exit tickets to gauge mastery and assign homework: three practice problems (one series, one parallel, one resistivity) to be completed before the next class.