Ray Optics – Complete Notes for Class 12 CBSE

 <b>Introduction</b><br>

Ray Optics is an important chapter in Class 12 Physics that deals with the behavior of light when it travels in straight lines. This chapter includes topics like reflection, refraction, lenses, mirrors, and optical instruments.<br><br>


<b>🔹 Important Concepts</b><br><br>


<b>1. Laws of Reflection</b><br>

- The angle of incidence = angle of reflection<br>

- Incident ray, reflected ray, and normal lie in the same plane<br><br>


<b>2. Refraction of Light</b><br>

- When light passes from one medium to another, it bends.<br>

- Snell’s Law: <br>

n₁ sin i = n₂ sin r<br><br>


<b>3. Lens Formula</b><br>

1/f = 1/v – 1/u<br><br>


<b>4. Mirror Formula</b><br>

1/f = 1/v + 1/u<br><br>


<b>5. Power of a Lens</b><br>

P = 100/f (in cm)<br>

Unit: Dioptre (D)<br><br>


<b>🔹 Important Ray Diagrams</b><br>

- Ray parallel to principal axis passes through the focus.<br>

- Ray passing through optical center goes undeviated.<br><br>


<b>🔹 Applications of Ray Optics</b><br>

- Spectacles and contact lenses<br>

- Cameras and microscopes<br>

- Human eye functioning<br>

- Optical fibers<br><br>


<b>🔹 Exam Tips</b><br>

- Revise formulae daily<br>

- Draw ray diagrams neatly<br>

- Practice numerical questions regularly<br><br>


<b>🔚 Conclusion</b><br>

Ray Optics is full of logic and diagrams. Focus on understanding each concept clearly, and practice drawing ray diagrams to score well in exams.

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