Question

an object 3 centimetres height is placed at a distance of 10cm in front of a converging mirror of focal length 20 cm .find the position nature and size of the image formed​

Answer 1

★★Question:-

✓✓An object 3 cm high is placed at a distance of 10 cm in front of a converging mirror of focal length 20 cm. Find the position, nature and size of the image formed.

★★Given:-

• Height of an object $(h1)=3cm$

• Distance of an object $(u) =-10cm$

• Focal length $(f)=-20cm$

★★Explanation:-

we know that,

$\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}$

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

$= \dfrac{1}{(-20)}-\dfrac{1}{(-10)}$

$=\dfrac{-1}{20} + \dfrac{1}{10}$

$=\dfrac{(-1 + 2)}{20}$

$=\dfrac{1}{20}$

$\boxed{\boxed{{∴v=20cm}}}$

The image is formed at a distance of 20 cm behind the mirror.

Then,

• h1= Height of object

• h2= Height of image

so,

$m=-\dfrac{v}{u} = \dfrac{h2}{h1}$

$⇒$$\dfrac{-20}{-10} = \dfrac{h2}{3}$

$⇒$$\boxed{\boxed{{h2=6cm}}}$✔️✔️

Image is 6cm in size, virtual and erect.