Practice and Revision - Refraction through a Lens
Let us practise and revise what we learned about refraction through a lens. Lenses refract light to form images, with convex lenses convergi
Core concept
The lens formula, 1/v - 1/u = 1/f, relates object distance (u), image distance (v), and focal length (f) for both convex and concave lenses.
How it works
Convex (converging) lenses can form real or virtual images depending on object position, used in magnifying glasses and cameras.
Why it matters
Concave (diverging) lenses always form virtual, diminished, upright images, commonly used to correct short-sightedness (myopia).
Key detail
Magnification (m = v/u = height of image/height of object) tells us how much larger or smaller the image is compared to the object.
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Quick notes
• Lens formula: 1/v - 1/u = 1/f.
• u=object distance, v=image distance, f=focal length.
• Convex lenses converge light.
• They can form real or virtual images.
• Concave lenses diverge light.
• They always form virtual, diminished images.
• Concave lenses correct myopia.
• Magnification = v/u = image height/object height.