CBSE Class 10 Answered

Convex lens:

A lens that possesses at least one surface that is curved outward is known as a convex lens. If both the surfaces of the lens are curved outward, it is known as a biconvex lens. The image formed by a convex lens will be real and inverted, except when the object is between the focus and the optical center. When the object is between the focus and the optical center, the image formed will be virtual and erect. The image formed by the convex lens may be enlarged or diminished, according to the position of the object.

Concave lens:

A lens that possesses at least one surface that is curved inward is known as a concave lens. If both the surfaces of the lens are curved inward, it is known as a biconcave lens. The image formed by the concave lens will be always virtual and erect. The image formed by the concave lens will be always diminished.