Class 12 Physics — Chapter 1: RAY OPTICS AND OPTICAL INSTRUMENTS

What you'll learn

• ▸Laws of Reflection
• ▸Cartesian Sign Convention
• ▸Focal Length of Spherical Mirrors
• ▸Ray Diagrams for Spherical Mirrors
• ▸The Mirror Equation
• ▸Linear Magnification for Mirrors
• ▸Ray Optics Approximation

Chapter Summary

--- PAGE 1 --- Chapter Nine RAY OPTICS AND OPTICAL INSTRUMENTS 9.1 INTRODUCTION Nature has endowed the human eye (retina) with the sensitivity to detect electromagnetic waves within a small range of the electromagnetic spectrum. Electromagnetic radiation belonging to this region of the spectrum (wavelength of about 400 nm to 750 nm) is called light. It is mainly through light and the sense of vision that we know and interpret the world around us. There are two things that we can intuitively mention about light from common experience. First, that it travels with enormous speed and second, that it travels in a straight line. It took some time for people to realise that the speed of light is finite and measurable. Its presently accepted value in vacuum is c = 2.99792458 × 10⁸ m s⁻¹. For many purposes, it suffices to take c = 3 × 10⁸ m s⁻¹. The speed of light in vacuum is the highest speed attainable in nature. The intuitive notion that light travels in a straight line seems to co…

Practice Questions from this Chapter

Tap "Get Solution" on any question to ask our AI tutor.

1. Illustrate how mirrors flip images. Get Solution →
2. Show me real-world light ray examples. Get Solution →
3. Define focal length simply. Get Solution →
4. According to the text, what is the approximate range of wavelengths for visible light? Get Solution →
5. What is the path of light, considered as a straight line, called? Get Solution →
6. What is the first law of reflection regarding the angles of incidence and reflection? Get Solution →
7. What is the line joining the pole and the centre of curvature of a spherical mirror called? Get Solution →
8. According to the Cartesian sign convention, where are all distances measured from? Get Solution →

Did you know?

• 💡 Light can circle the Earth over seven times in a single second.
• 💡 A rainbow forms because white sunlight splits into different colors.
• 💡 Your eye can detect a single photon of light in perfect darkness.
• 💡 The earliest mirrors were polished pieces of obsidian or metal.
• 💡 Light acts like both a wave and a particle simultaneously.

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