Question

A real object is 24 cm away from a convex lens of focal length 20 cm,
the image distance from convex lens is​

Answer 1

image distance from convex lens is 60

Answer 2

Given:

A real object is 24 cm away from a convex lens of focal length 20 cm.

To find:

Image distance from lens.

Calculation:

Applying Lens Formula with appropriate sign convention:

$\therefore \: \dfrac{1}{f} = \dfrac{1}{v} - \dfrac{1}{u}$

$= > \: \dfrac{1}{20} = \dfrac{1}{v} - \dfrac{1}{( - 24)}$

$= > \: \dfrac{1}{20} = \dfrac{1}{v} + \dfrac{1}{24}$

$= > \: \dfrac{1}{v} = \dfrac{1}{20} - \dfrac{1}{24}$

$= > \: \dfrac{1}{v} = \dfrac{6 - 5}{120}$

$= > \: \dfrac{1}{v} = \dfrac{1}{120}$

$= > \: v = 120 \: cm$

So, a real image will be formed 120 cm from the convex lens.

Characteristics of image:

• Image will be real.

• Image will be inverted.

• Image will be magnified.