Question

One half of a convex lens of focal length 10 cm is covered with a black paper. can such a lens produce an image of a complete object placed at a distance of 30 cm from the lens? Draw a ray diagram to justify your answer. A 4 cm tall object is placed perpendicular to its principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 15 cm. Find the nature, position and the size of the image.

Answer 1

$\frac{1}{v}-\frac{1}{4}=\frac{1}{f}$

$\frac{1}{v}=\frac{1}{24}+\frac{1}{(-16)}$

$v=-48cm$

$m=\frac{v}{u}=\frac{-48}{-16}=3,$

$\frac{hi}{h_0}=\frac{hi}{3}$

The image is enlarged and erect.