Ray Optics and Optical Instruments — Class 12 Physics NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 12 Physics chapter "Ray Optics and Optical Instruments" — 8 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 12 Physics chapter "Ray Optics and Optical Instruments" — 8 important questions with detailed answers for…
By Syllab.in · Updated
Key Questions Covered:
- What is refraction? State Snell's law and derive it using Huygens' principle.
- Define critical angle and total internal reflection. For glass (n = 1.5), fin…
- Derive lens maker's formula and show how it relates object distance, image di…
- + 5 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| What is refraction? State Snell's law and derive it using… | ✓ Solved |
| Define critical angle and total internal reflection. For … | ✓ Solved |
| Derive lens maker's formula and show how it relates objec… | ✓ Solved |
Showing 3 of 8 questions
Q1: What is refraction? State Snell's law and derive it using Huygens' principle.
Refraction: Bending of light ray at the interface between two media of different optical densities.
Snell's Law: n₁ sin θ₁ = n₂ sin θ₂
Where n₁, n₂ are refractive indices; θ₁, θ₂ are angles of incidence and refraction.
Derivation using Huygens' Principle:
Consider plane wavefronts AB and A'B' inci...
Q2: Define critical angle and total internal reflection. For glass (n = 1.5), find critical angle.
Critical Angle: Angle of incidence in denser medium for which angle of refraction is 90°.
Total Internal Reflection: Complete reflection of light at interface from denser to rarer medium when angle of incidence exceeds critical angle.
Derivation:
At critical angle θ_c, refraction angle = 90°
Using...
Q3: Derive lens maker's formula and show how it relates object distance, image distance, and focal length.
Lens Maker's Formula: 1/f = (n - 1)[1/R₁ - 1/R₂]
Where n = refractive index, R₁, R₂ = radii of curvature
Derivation:
Consider a thin lens with radii R₁ (first surface) and R₂ (second surface).
For refraction at first surface (air to glass):
1/s₁ + n/s₁' = (n-1)/R₁
For refraction at second surface...
Showing 3 of 8 questions. Visit the full page for complete solutions.