Which one among the following is used in a simple microscope ?

A simple microscope consists of a single biconvex lens, which is a type of converging lens [1]. A converging lens is thicker at the center than at the edges and has the property of focusing parallel incident light rays toward a common focal point [1]. When an object is placed within the focal length of this lens, it produces a virtual, upright, and magnified image, which is the fundamental principle of a magnifying glass or simple microscope. In contrast, diverging lenses (concave lenses) cause light rays to spread out and typically form diminished images, making them unsuitable for magnification in a simple microscope [1]. While compound microscopes use multiple lenses, the simple microscope relies solely on the refractive properties of a single converging lens to make small objects appear larger.

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 10: Light: Mirrors and Lenses > Activity 10.10: Let us investigate > p. 164