CBSE Class 12 Physics – Ray Optics and Optical Instruments

Chapter Overview

This chapter focuses on geometrical optics where light is treated as rays. You’ll study reflection by plane and spherical mirrors, refraction through lenses and prisms, total internal reflection, dispersion, and the formulas for image formation. It then applies these principles to optical instruments—microscopes, telescopes, cameras, and spectrometers.

Important Keywords

• Ray Optics: Light modeled as rays traveling straight. :contentReference[oaicite:1]{index=1}
• Reflection: Light bounces off surfaces obeying angle of incidence = angle of reflection. :contentReference[oaicite:2]{index=2}
• Refraction: Bending of light at boundary—governed by Snell’s law (n₁ sinθ₁ = n₂ sinθ₂). :contentReference[oaicite:3]{index=3}
• Total Internal Reflection: Occurs when angle exceeds critical angle in denser-to-rarer medium. :contentReference[oaicite:4]{index=4}
• Lens/Mirror Formula: 1/f = 1/v + 1/u; magnification m = v/u. :contentReference[oaicite:5]{index=5}
• Prism Dispersion: Spreading of white light into spectrum. :contentReference[oaicite:6]{index=6}
• Microscope & Telescope: Two-lens systems for magnification. :contentReference[oaicite:7]{index=7}
• Spectrometer: Measures light properties via dispersion. :contentReference[oaicite:8]{index=8}