Question

An object is placed in front of a convex lens of focal length 8.0 cm.A virtual image formed at 2.0 cm from the lens. What is the object distance​

Answer 1

Explanation:

The object is at U=18cm

Answer 2

Explanation:

Given :

f = 8 cm

v = 2 cm

u = ?

Using lens formula,

$\large \color{yellow} \: \frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

$\frac{1}{8} = \frac{1}{2} - \frac{1}{u}$

$\large \frac{1}{u} = \frac{1}{2} - \frac{1}{8} = \frac{8 - 2}{16}$

$\frac{1}{u} = \frac{6}{16}$

=>u= 16/6 = 2.6cm