Light travels in straight lines . However ,it can change direction when it moves into a different material. This is called REFRACTION.
Refraction in lenses🤓
A lens is a transparent that has been shaped so that its interface changes the directions of parallel light waves.
A coverging/convex lens is a glass block that is curved on both sides to make it thicker in the middle. When light rays enter it comes together. A convex lens focuses the rays.
The distance between the focus and the lens is called the FOCAL LENGTH.
In I/GCSE Physics, you have to learn how to measure the focal length...
You can measure the focal length by by focusing the image of a distant object on a piece of paper.
In a refracting telescope , a convex lens creates an image inside the tube and the other lens is used to magnify this image.
Refraction occurs because light travels at different speeds in different materials.
That's the end of the topic!
Drafted by Catrina (Physics)