Question

The magnification of an image formed by a lens is -1. If the distance of image

from the lens is 25 cm. then find the nature and focal length of lens. ​

Answer 1

It is is aconvex lens. since magnification is negative.

now,

m= -1

u= -25

v=?

f=?

so, m=v/u

.. -1=v/-25

v= 25cm

now,. 1/v - 1/u= 1/f

1/f = 1/25 - (1/-25)

. = 1/25 + 1/25

= 2/25

f. = 25/2

f = 12.5cm

focallength=12.5cm

hope it helps u......

and. pls mark my ans as brainliest.......