Question

An object of height 2 cm is placed at a distance of 15 cm from concave lens of power -10 D . Find the height of an image.​

Answer 1

Spherical lenses are the lenses formed by binding two spherical transparent surfaces together. Spherical lenses formed by binding two spherical surfaces bulging outward are known as convex lenses while the spherical lenses formed by binding two spherical surfaces such that they are curved inward are known as concave lenses.

Answer:

$\sf{hi= \:0.8cm}$

Given:

$\sf{ho\:= \:2cm}$

$\sf{u \:= \:-15cm}$

$\sf{Power \:of \:lens \:= \:-10D}$

$\sf{Lens \:= \:Concave \:lens}$

To Find:

Height of image

Answer:

$\sf{{P=}{\dfrac{1}{f}}}$

$\sf{{f=}{\dfrac{1}{P}}}$

$\sf{{f=}{\dfrac{-1}{10}}}$

$\sf{f=-0.1m \:or -10cm}$

From Lens Formula:

$\sf{{\dfrac{1}{f}}={\dfrac{1}{v}}-{\dfrac{1}{u}}}$

$\sf{{\dfrac{-1}{10}}={\dfrac{1}{v}}+{\dfrac{1}{u}}}$

$\sf{{\dfrac{1}{v}}=-{\dfrac{1}{10}}-{\dfrac{1}{15}}}$

$\sf{v= \:-6cm}$

$\sf{{\dfrac{hi}{ho}}={\dfrac{v}{u}}}$

$\sf{{\dfrac{hi}{2}}={\dfrac{-6}{-15}}}$

$\sf{{hi}={\dfrac{12}{15}}}$

$\sf{hi= \:0.8cm}$

Answer 2

Spherical lenses are the lenses formed by binding two spherical transparent surfaces together. Spherical lenses formed by binding two spherical surfaces bulging outward are known as convex lenses while the spherical lenses formed by binding two spherical surfaces such that they are curved inward are known as concave lenses.