Physics

Problem

A thin concave lens forms a virtual image

15\,\text{cm}

from the lens on the same side as the object. The object is

30\,\text{cm}

from the lens. Which one of the following correctly lists the signs of

u

(object distance),

v

(image distance),

f

(focal length) and

m

(magnification) according to the Cartesian sign convention? a)

u

: negative,

v

: positive,

f

: negative,

m

: positive b)

u

: positive,

v

: negative,

f

: negative,

m

: positive c)

u

: negative,

v

: negative,

f

: negative,

m

: positive d)

u

: negative,

v

: negative,

f

: positive,

m

: positive