Physics

Problem

A lens forms a sharp real image of an object on a screen

60\,\text{cm}

away when the object is placed

30\,\text{cm}

from the lens on the opposite side. Which choice correctly identifies the lens type and its focal length? a) Convex lens,

15\,\text{cm}

b) Convex lens,

20\,\text{cm}

c) Concave lens,

-60\,\text{cm}

d) Convex lens,

60\,\text{cm}