Physics Class 12 — Introduction to Ray Optics and Light + 8 more topics

Light is fundamentally an electromagnetic wave, meaning it's made up of oscillating electric and magnetic fields that travel through space. It doesn't need a medium (like air or water) to travel, which is why light from the sun reaches us through the vacuum of space. The speed of light in a vacuum, denoted as $c$, is approximately $3 \times 10^8$ meters per second, which is incredibly fast!

When light hits a spherical mirror, it reflects in a predictable way. The shape of the mirror dictates how the light rays behave, which in turn determines the characteristics of the image formed (e.g., its size, orientation, and whether it's real or virtual).

Refraction is the phenomenon where a light ray changes its direction as it passes from one transparent medium to another. This happens because light travels at different speeds in different media.

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When light travels from one transparent medium to another through a spherical surface, it bends. This bending is called refraction. The key here is that the surface is curved, not flat like a window pane.

We have a formula to describe this:

$$ \frac{n_2}{v} - \frac{n_1}{u} = \frac{n_2 - n_1}{R} $$

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