Topical: Physics- Lenses 1

For Term 3 of 2011 (sec 2) we learnt more about physics and explicitly, lenses. Lenses are basically small glass blocks that will either converge or diverge the rays. Lenses that diverge rays of light when they pass through the lens are called Concave Lenses. Lenses that converge rays of light when they pass through the lens are called Convex Lenses. In our curriculum we focused more on Convex Lenses.

Convex lenses as stated previously, converge the rays to a certain point as they pass through the lens. The image that is produced, however, depends a lot on the distance between object and the lens itself. The focal point is the point at which initially parallel rays of light meet after passing through a convex lens. Let f be the focal distance which is the distance between the focal point and the lens. When the object is more than 2f away from the lens itself, the image produced is diminished, inverted and real. When the object is between 2f and f away from the lens itself, the image is enlarged, inverted and real. When the object is exactly f away from the lens, there will be no image formed! When the object is less than f away from the lens, the image formed will be enlarged, upright and virtual. The image is formed in front of the lens instead!