Скачать или смотреть Numericals of Ray Optics | Class 12 | Physics | CBSE 2026

A fast-paced, exam-focused walkthrough of key ray optics numericals for Class 12 CBSE 2026. We revise core formulas and signs conventions, then applies them to mirrors, lenses, refraction, prisms, optical fibers, microscopes, and telescopes. Each segment demonstrates the method, highlights common pitfalls (like sign conventions and which formula variant to use), and ends with clean results so you can build a reliable formula sheet and master PYQs.

00:00: Introduction, plan, and formula-sheet advice.
01:06: Problem 1 — Concave mirror: position, nature, size; mirror formula and magnification.
04:08: Problem 2 — Convex mirror: image position, nature, size; magnification sign.
08:12: Problem 3 — Convex lens: lens formula, image position; magnification exercise.
09:54: Problem 4 — Concave lens: given image distance; find object distance and magnification.
12:11: Problem 5 — Lens Maker’s Formula: plano‑convex lens; R1=∞ handling.
14:52: Problem 6 — Power of lenses in contact: net power and focal length.
16:51: Problem 7 — Combination of convex + concave lenses: net focal length and final image.
19:15: Problem 8 — Apparent depth in water tank: refractive index from real/apparent depth.
20:38: Problem 9 — Glass slab lateral displacement: Snell’s law → r, then displacement formula.
24:15: Problem 10 — Prism deviation (i=e): δ = i + e − A with equilateral prism.
26:02: Problem 11 — TIR condition at second face: find i using critical angle; Snell at first face.
28:42: Problem 12 — Optical fiber: numerical aperture and acceptance angle.
32:02: Problem 13 — Simple microscope: magnifying power at D and at ∞.
34:13: Problem 14 — Compound microscope: m_objective, m_eyepiece, total magnification.
38:56: Problem 15 — Astronomical telescope (normal adjustment): M and tube length L.
41:47: Problem 16 — Telescope (image at near point): find f_objective and f_eyepiece from M and L.
44:59: Problem 17 — Prism at minimum deviation: μ from A and δ_min.
47:16: Final numerical — Concave mirror recap: position, inverted real image, magnification.

Topics Covered
Sign conventions and core formulas: mirror formula, lens formula, magnification.
Lens Maker’s Formula; handling plano/convex surfaces and R=∞.
Powers of lenses and focal length of combinations (in contact and separated).
Refraction: apparent depth; Snell’s law applications; glass slab lateral displacement.
Prisms: deviation, minimum deviation, and μ–A–δ_min relation.
Optical fiber: numerical aperture and acceptance angle (TIR-based).
Optical instruments: simple/compound microscope magnification; astronomical telescope magnifying power and tube length.

Important Links
[Class Notes PDF (Ray Optics Numericals)](https://drive.google.com/file/d/1WdfO...)

Tags
#cbse #class12physics #physics #boardexams2026 #backbenchersphysics #top