Скачать или смотреть Class 10 Science Ch-10 Part-2 |Rainbow Formation 🌦️|Dispersion & Scattering of Light |Boards 2026 📘🔥

✨📘 Class 10 Science | Chapter-10 Part-2 – The Human Eye & the Colourful World 🌍🌈
In this video, Vishal Sir explains Rainbow Formation 🌦️, Dispersion of Light 🔺, and Scattering of Light ✨ in a simple & exam-oriented way for Class 10 students.
👉 Learn how a rainbow is formed using refraction, dispersion & total internal reflection 🌈
👉 Understand why the sky is blue 💙 and sun looks red at sunrise & sunset 🌅
👉 Concept of dispersion through prism 🔺 explained with easy examples
👉 Scattering of light & Rayleigh scattering made crystal clear 💡
👉 Important NCERT points + Board PYQs 🔥
📌 Perfect for Boards 2026 preparation
📌 Helpful for 1–5 mark questions
📌 Best for revision before exams 📝
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📚 Study smart with Vishal Sir – Science made easy! 🚀
Notes for this video-

1. Rainbow-
A rainbow is a natural spectrum of sunlight seen in the sky after rain.
Formation of Rainbow
Rainbow is formed due to three processes: 1️⃣ Refraction of sunlight when it enters raindrop
2️⃣ Dispersion of light into seven colours (VIBGYOR)
3️⃣ Total Internal Reflection inside the raindrop
4️⃣ Refraction again when light comes out
Order of Colours
👉 V I B G Y O R
Red → outermost
Violet → innermost
Conditions to See Rainbow
Sun behind the observer ☀️
Water droplets in front 🌧️
Sun low in the sky
🔺 2. Dispersion of Light-
Dispersion: Splitting of white light into its constituent colours when it passes through a glass prism.
Important Points
White light = mixture of 7 colours
Different colours have different wavelengths
Violet deviates most, Red deviates least
Spectrum
The band of seven colours obtained is called a spectrum.
🔄 Recombination of Spectrum-
When spectrum is passed through an inverted prism, white light is obtained again.
Proves that white light is a mixture of colours.
✨ 3. Scattering of Light
Scattering: Bending and spreading of light in different directions when it strikes small particles.
Rayleigh Scattering
Amount of scattering ∝ 1 / (wavelength)⁴
Shorter wavelength → more scattering
💙 Why is the Sky Blue?
Blue light has shorter wavelength
It scatters more than red light
Hence, sky appears blue
🌅 Why Sun Appears Red at Sunrise & Sunset?
Sunlight travels longer distance in atmosphere
Blue light scatters away
Red light reaches eyes → sun looks reddish
🚦 Why are Danger Signals Red?
Red has longest wavelength
Least scattering
Visible from long distances
🌫️ 4. Tyndall Effect
Scattering of light by colloidal particles, making the light path visible.
Examples:
Sunlight in dusty room
Vehicle headlights in fog
🌍 5. Atmospheric Refraction
Refraction of light due to different layers of atmosphere.
Effects:
Twinkling of stars
Advance sunrise & delayed sunset
🔑 Exam Key Points (Boards 2026)
✔ Rainbow → refraction + dispersion + total internal reflection
✔ Sky blue → scattering of blue light
✔ Sunrise/sunset red → scattering of blue light
✔ Prism causes dispersion
✔ Red deviates least, violet most