Physics

Problem

For a thin lens, the lens formula relates the focal length

f

, the object distance

u

and the image distance

v

. a. (i) Starting from the lens formula, derive an expression for the linear magnification

m

of the lens in terms of

u

and

f

only. b. (ii) Using the expression obtained in part (i), calculate the object distance for which a lens of focal length

12\,\text{cm}

produces an image with magnification

m=-2

. c. (iii) State two characteristics of the image obtained in part (ii).