Physics

Problem

A convex lens of focal length

12\,\text{cm}

is required to give an erect image twice the size of the object. At what distance from the lens should the object be placed (use sign convention)? a)

u = +6\,\text{cm}

u = -6\,\text{cm}

u = -18\,\text{cm}

u = -12\,\text{cm}