Question

Focal length of a convex lens is $20cm$ and its $RI$ is $1.5$. It produces an erect, enlarged image if the distance of the object from the lens is

• A. 40 cm
• B. 30 cm
• C. 15 cm
• D. 20 cm

Answer 1

Answer: (C)

Focal length $=20cm$
Refractive index, $\mu =1.5$
A convex lens produces an erect and enlarged image only when a real object is placed between focus and optical centre.

$\therefore$ Distance $=15cm$