Answer the following for a thin convex lens:

PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction

Problem

Answer the following for a thin convex lens: (a) Derive the lens formula relating

u

v

and

f

using the Cartesian sign convention. (b) An object is placed

30\,\text{cm}

in front of the lens whose focal length is

20\,\text{cm}

. Calculate the image distance and comment on whether the result is consistent with the derived formula.