Physics X - Chapter 10 Light – Reflection and Refraction
Master Light Reflection and Refraction with Class 10 MCQs. Practice mirror formula, lens formula, and light phenomena for physics board exams.
Quick Revision : Light – Reflection and Refraction
- Rectilinear Propagation: Light travels in straight lines in a homogeneous medium.
- Reflection: Angle of incidence = Angle of reflection; i = r.
- Plane Mirror: Forms virtual, erect, same-sized image; shows lateral inversion.
- Spherical Mirrors: Concave (converging) & Convex (diverging); Pole, Focus, Center of Curvature.
- Mirror Formula: 1/v + 1/u = 1/f; Sign convention: u = -ve, f (concave) = -ve, f (convex) = +ve.
- Magnification: m = -v/u = h'/h; m > 0: virtual & erect; m < 0: real & inverted.
- Refraction: Bending of light when passing from one medium to another.
- Snell's Law: n₁ sin i = n₂ sin r; Light bends towards normal in denser medium.
- Refractive Index: n = c/v; determines optical density; n(air) ≈ 1, n(water) = 4/3, n(glass) ≈ 1.5.
- Lens Formula: 1/v - 1/u = 1/f; Sign convention: u = -ve, f (convex) = +ve, f (concave) = -ve.
- Lens Power: P = 1/f (in meters); Unit: Dioptre (D); Convex: +ve, Concave: -ve.
- Human Eye: Retina = screen; Cornea + Lens focus light; Ciliary muscles adjust focal length (accommodation).
- Defects of Vision: Myopia (nearsighted) – concave lens; Hypermetropia (farsighted) – convex lens.
- Dispersion: Splitting of white light into VIBGYOR by a prism; Red deviates least, Violet most.
- Atmospheric Refraction: Causes twinkling of stars, advanced sunrise, delayed sunset.
- Critical Angle & TIR: sin C = 1/n; Total Internal Reflection when i > C; used in optical fibres.
Basic Level Questions
Chapter Summary: Light – Reflection and Refraction
This chapter illuminates the fundamental principles that govern how light interacts with surfaces and materials—explaining everything from why you see your reflection in a mirror to why a straw appears bent in a glass of water. It connects everyday observations to scientific laws that form the basis of optics.
This is a high-scoring chapter (10-12 marks) in board exams and competitive tests like NTSE and Olympiads. Expect numerical problems on mirror/lens formulas, diagram-based questions on ray tracing, and conceptual questions on vision defects and atmospheric phenomena. A strong grasp of sign conventions and formula applications can secure easy marks. The chapter's concepts are also foundational for future studies in physics, engineering, and medical sciences.
Our platform transforms abstract optical concepts into clear, exam-ready knowledge through 130+ graded MCQs. From basic definitions to complex numerical applications, you'll practice every formula, diagram, and concept. The instant feedback helps you master tricky sign conventions and avoid common mistakes in calculations. This targeted practice builds the speed and accuracy needed to solve optics problems quickly, turning light and vision concepts into guaranteed marks on your exam paper.