1. CONVEX LENS

2. Focus
Convex lens is thicker in the middle and thinner at the edges. Rays of light parallel to the principal axis after refraction through a convex lens meet at a point (converge) on the principal axis. That point is called focus.

3. Images formed by Convex Lens
When the object is placed beyond 2F, the image is formed between F and 2F on the other side of the lens.
Image is diminished, real and inverted.

4. Images formed by Convex Lens
When the object is placed at 2F, the image is formed at 2F on the other side of the lens.
Image is of the same size as that of the object, real and inverted.

5. Images formed by Convex Lens
When the object is placed between F and 2F, the image is formed beyond 2F on the other side of the lens.
Image is magnified, real and inverted.

6. Images formed by Convex Lens
When the object is placed at F, the image is formed at infinity or practically we can’t see the image.
Image is magnified, real and inverted (!!).

7. Images formed by Convex Lens
When the object is placed between F and Pole, the image is formed on the same side of the object.
Image is magnified, virtual and upright. (It is a magnifying glass)

8. Lens formula ƒ = focal length u= object distance v= image distance
f is negative for convex mirrors and concave lenses.
This formula is general and valid in all situations for any spherical lens.
Take proper care of the signs of different quantities while solving problems.

9. Magnification m = magnification h’= image height h = object height
Magnification is defined as the ratio of the image height to the object height.

10. Power of a convex lens is positive.
Power of convex lens
P = Unit power of a lens is dioptre (D)
f = focal length of the lens in meter
Power of a convex lens is positive.

11. Convex lens
Thank you.