An object is placed 10 cm in front of a convex lens of focal length 15 cm. The image produced will be

For a convex (converging) lens, the focal length (f) is positive. According to the lens formula 1/f = 1/v - 1/u, where u is the object distance and v is the image distance [1]. In this scenario, the object is placed at u = -10 cm and the focal length is f = +15 cm. Since the object is positioned within the focal length (u < f), the light rays diverge after passing through the lens. Calculating the image distance gives 1/v = 1/15 + 1/(-10), resulting in v = -30 cm. A negative image distance indicates a virtual image formed on the same side as the object. Furthermore, the magnification (m = v/u) is +3, which signifies that the image is upright and magnified. Therefore, when an object is closer to a convex lens than its focal point, it produces a virtual and magnified image.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > 9.3.7 Lens Formula and Magnification > p. 155