Question

(OR]
An object is kept at a distance of 40cm from a diverging lens of focal length 20cm. At what distance
the image is formed from the lens? Find the magnification of the image.​

Answer 1

$\sf\small\red{Given:-}$

$\sf\hookrightarrow \: u = - 40cm$

$\sf\hookrightarrow \: v = - 20cm$

$\sf\small\red{Find:-}$

$\sf\rightarrow \: find \: the \: magnification \: of \: the \: image.$

$\sf\small\red{Solution:-}$

$\sf\rightarrow \: \frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

$\sf\rightarrow \: \frac{1}{f} = \frac{1}{ - 20} - \frac{1}{ - 4 0}$

$\sf\rightarrow \: \frac{1}{ - 40} - \frac{1}{20}$

$\dashrightarrow\sf \fbox \red{f = 40cm}$

Magnification,

$\sf\rightarrow \: f_{(m)} = \frac{40}{100}$

$\sf\rightarrow \: p = \frac{1}{f(m)}$

$\sf\rightarrow \frac{1}{( \frac{40}{100}) }$

$\sf\rightarrow \frac{ - 100 }{40}$

$\sf \dashrightarrow \red 2.5 \: D$