Question

A concave lens has focal length of 15 cm. At what distance should
the object from the lens be placed so that it forms an image at 10 cm
from the lens? Also, find the magnification produced by the lens.​

Answer 1

A꙰N꙰S꙰W꙰E꙰R꙰

Given :

f = - 15 cm

v = - 10 cm

To Find:

u = ??

m = ??

solution:

Using 1/v - 1/u = 1/f, we get

⇒ 1/- 10 - 1/u = 1/- 15

⇒ 1/u = - 1/10 + 1/15

⇒ 1/u = - 3 + 2/30

⇒ 1/u = 1/30

⇒ u = - 30 cm

Magnification , m = v/u

⇒ m = - 10/- 30

⇒ m =  1/3

Hence, The magnification produced by lense is 1/3.

hope these will help you...

please mark as brainliest...

Answer 2

★★Question;-

A concave lens has focal length of 15 cm. At what distance should the object from the lens be placed so that it forms an image at 10 cm from the lens ? Also find the magnification produced by the lens.

★★Given;-

• focal length (F)=-15 cm after sign conventions

• Image distance(V)=-10cm

• Object distance(U)=?

★★Answer;-

By using formula,

$\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$

$\frac{1}{-10}-\frac{1}{u}=\frac{1}{-15}$

$\frac{1}{u}=-\frac{1}{10}+\frac{1}{15}$

$\frac{-3+2}{30}=-\frac{1}{30}$

$⇢$$\boxed{\boxed{{U=-30cm}}}$

Magnification,

$m=\frac{u}{v}=\frac{-10}{-30}$

$\boxed{\boxed{{Magnification=\frac{1}{3}}}}$