Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Physics
Lesson Topic: understand that polarisation is a phenomenon associated with transverse waves
Learning Objective/s:
  • Describe what polarisation is and why it only occurs in transverse waves.
  • Identify and differentiate linear, circular, and elliptical polarisation states.
  • Apply Malus’s law to calculate transmitted intensity for different analyser angles.
  • Explain how polarising filters, reflection, and scattering produce polarised light.
  • Evaluate real‑world applications of polarisation such as sunglasses, LCDs and stress analysis.
Materials Needed:
  • Projector or interactive whiteboard
  • Slides with diagrams of polarisation and Malus’s law
  • Polaroid filters and a light source for demonstration
  • Worksheet with practice calculations
  • Calculator for each student
  • Laptop with simulation software (optional)
 Introduction:
Begin with a quick demonstration: shine a flashlight through a Polaroid filter and rotate it to show changing brightness. Ask students what determines the direction of the light’s vibration and recall that only transverse waves have a direction perpendicular to propagation. Explain that today they will understand polarisation as a property of transverse waves and will be able to predict intensity using Malus’s law.
Lesson Structure:
  1. Do‑now (5'): students answer a short question on wave types on the board.
  2. Mini‑lecture (10'): definition of polarisation and why only transverse waves can be polarised, using slides.
  3. Demonstration (8'): use Polaroid filters and a laser pointer to show linear polarisation and Brewster’s angle.
  4. Interactive activity (12'): groups calculate transmitted intensity with Malus’s law for various angles using worksheets.
  5. Exploration (10'): discuss circular and elliptical polarisation; watch a short simulation video.
  6. Application discussion (8'): link polarisation to sunglasses, LCDs, stress analysis; students list examples.
  7. Quick check (5'): exit ticket – one sentence describing how a polarising filter works.
Conclusion:
Summarise that polarisation is a characteristic of transverse waves, described by the orientation of the electric field and quantified by Malus’s law. Students submit an exit ticket stating one real‑world use of polarisation. For homework, assign a problem set on intensity calculations and a short research task on a modern polarisation technology.