Question

A needle 10 cm high is placed at 40 cm from a convex lens of focal length 15 cm find position nature and size of image also draw ray diagram​

Answer 1

Above is the answer!!!!

Answer 2

Given:

A needle 10 cm high is placed at 40 cm from a convex lens of focal length 15 cm.

To find:

• Image position
• Image characteristics

Calculation:

Applying Len's Formula:

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

$\rm \implies \dfrac{1}{15} = \dfrac{1}{v} - \dfrac{1}{( - 40)}$

$\rm \implies \dfrac{1}{15} = \dfrac{1}{v} + \dfrac{1}{40}$

$\rm \implies \dfrac{1}{v} = \dfrac{1}{15} - \dfrac{1}{40}$

$\rm \implies \dfrac{1}{v} = \dfrac{8 - 3}{120}$

$\rm \implies \dfrac{1}{v} = \dfrac{5}{120}$

$\rm \implies v = 24 \: cm$

• So, image distance is 24 cm.
• Image is real, inverted and diminished.

Hope It Helps.