Question

The relation between the linear magnification m, the object distance u and the focal length f is
(a) $m= \frac{f-u}{f}$
(b) $m= \frac{f}{f-u}$
(c) $m= \frac{f+u}{f}$
(d) $m= \frac{f}{f+u}$

Answer 1

i think B option is correct answer ......

Answer 2

Answer:

b)  m = f/(f-u)

Explanation:

The relationship between magnification and focal length for different optical instruments or devices is different.

Magnification = Image distance / Object distance

M = V / u

For a single thin lens, the magnification, m will be different and can be written as -

=  m = f/(f-u)

where f is the focal length of the thin lens and u is the distance between the object and the lens.

Thus, The relation between the linear magnification m, the object distance u and the focal length f is  m = f/(f-u).