Question

An object is placed at a distance of 30 cm from a concave lens of focal length 15 cm. An erect and virtual image is formed at a distance of 10 cm from the lens. Calculate the magnification.

Answer 1

Type of lens is Cancave lens. 

Formula: 

Magnification m = \(\frac{u}{v}\)

Object distance u = -30 cm 

Image distance v = -10 cm

m = \(\frac{-10}{-30}\) = \(\frac{1}{3}\) = +0.33