Difference between Convex and Concave lens
Convex lens
1.) The spherical lens which is thicker ( bulged outwards ) at centre and thinner at ends is known as convex lens
2.) The typical concave mirror is shown in fig. below.
3.) Convex lens collects all the refracted rays at the same point on its principal axis, known as convergence of refracted rays.
4.) The point of concurrence of refracted rays by convex lens is called as Focus of lens.
5) When an object is kept in front of convex lens, it produces real, inverted image of object.
6.) Convex lens are very useful for magnification purpose.
7.) Principal focus of convex lens appears behind lens, hence the focal length is taken as positive.
8.) Convex lens are used in microscopes and telescopes to see micro objects and distinct objects.
Concave lens
1.) The spherical lens which is thinner ( bulged inwards ) at centre and thicker at ends is known as concave lens
2.) The typical concave mirror is shown in fig. below.
3) Convex lens splits all the refracted rays from the same point on principal axis, known as divergence of refracted rays.
4) The point of concurrence of refracted rays by concave lens is called as Focus of lens.
5) When an object is kept in front of concave lens, it produces virtual, erected image of object.
6) Concave lens are very useful correction of defects like near-sightedness or myopia.
7) Principal focus of concave lens appears in front of lens, hence the focal length is taken as negative.